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Constipation

Overview

Constipation is associated with difficult or painful passage of stools and delayed frequency of stools that lasts at least 2 weeks. [Levy: 2016] [Varier: 2013] Normal stooling patterns change as children age. Newborns typically pass their initial stool (meconium) in the first 2 days. The pattern in infants can range from multiple stools daily to 1 stool every 10-14 days; the latter is more common in breastfed infants. During toilet training, children may have more episodes of constipation as they learn to attend to their body’s signals. For children ages 4 and older, 1 daily stool is typical. Stool consistency is considered normal when the stools are soft and mushy or formed. About 85% of people have a hard stool (fecal ball) present in the rectum after waking up, which is not the same as being constipated. [Varier: 2013] Although constipation may have several etiologies, functional constipation, which involves no underlying medical condition, is the most common type experienced by children.

Other Names & Coding

ICD-10 coding

K59.00, unspecified

K59.01, slow transit constipation

K59.09, other constipation

ICD-10 for Constipation provides further coding details.

Prevalence

The prevalence of constipation in children is about 12%. [Mugie: 2011] Constipation is responsible for 3% of all primary care visits for children and 10-25% of pediatric gastroenterology visits.  [Tabbers: 2014]

Genetics

Numerous genetic syndromes are associated with childhood constipation. Genetic factors are also thought to play a role in functional constipation, but linkage studies, association studies, and direct gene sequencing have yet to find associated gene mutations.  [Peeters: 2011]

Prognosis

Most children with functional constipation require prolonged treatment. In one study, after intensive initial medical and behavioral treatment, 60% of children were treated successfully at 1 year of follow-up and 80% at 8 years. One-third of the children needing follow-up beyond puberty continued to have severe complaints of constipation. [van: 2003]

Practice Guidelines

Tabbers MM, DiLorenzo C, Berger MY, Faure C, Langendam MW, Nurko S, Staiano A, Vandenplas Y, Benninga MA.
Evaluation and treatment of functional constipation in infants and children: evidence-based recommendations from ESPGHAN and NASPGHAN.
J Pediatr Gastroenterol Nutr. 2014;58(2):258-74. PubMed abstract / Full Text

Benninga MA, Faure C, Hyman PE, St James Roberts I, Schechter NL, Nurko S.
Childhood Functional Gastrointestinal Disorders: Neonate/Toddler.
Gastroenterology. 2016. PubMed abstract

Hyams JS, Di Lorenzo C, Saps M, Shulman RJ, Staiano A, van Tilburg M.
Functional Disorders: Children and Adolescents.
Gastroenterology. 2016. PubMed abstract

Roles of the Medical Home

The goals of constipation management by the medical home clinician include early recognition and effective management to prevent unnecessary emergency room visits and hospitalizations, as well as morbidity and mortality related to severe constipation. Successful therapy requires prevention and treatment of fecal impaction with oral laxatives or rectal therapies, increased dietary fiber, family education about withholding behaviors, and behavioral interventions.  [Nurko: 2014]

Clinical Assessment

Overview

Constipation can occur for several reasons:
  • Poor involuntary or voluntary neurologic control and muscle coordination in the GI tract, which can be due to chronic overstretching from retained or backed-up stool, surgical disruption, abnormal anatomy, and decreased neuroregulation
  • Dietary factors including inadequate fluid (especially water); inadequate fiber (found in whole grains, fruits, and vegetables); constipating foods (such as infant rice cereal, bananas, and cheese); lack of stimulating foods (such as prunes, or apple and pear juice); and unstructured grazing (instead of eating regular meals, thus losing the peristaltic stimulus of a food bolus)
  • Emotional factors including anxiety over painful stools, withholding behaviors that develop after having painful/hard stools, toileting accidents or stressful training, anxiety about asking to use the bathroom, and difficulty relaxing while in the bathroom
  • Lifestyle factors including inadequate exercise and lack of access to unhurried toilet time after meals or when the rectum feels full
  • Intake of certain medications (antacids with calcium or aluminum, antidepressants, antihistamines, narcotics, some antihypertensives, anticonvulsants, and antipsychotics) or iron supplements (however, the iron fortification in infant formula is not considered a contributing factor). See Medications That Can Affect Colonic Function (IFFGD) for a more complete list.
Pain-Retention Cycle in Constipation
Withholding stool can lead to a pain-retention cycle that exacerbates constipation. Withholding stool can lead to bulky, hard stools as the intestine reabsorbs more water when the stool does not pass. Pain associated with constipation can lead to not wanting to pass the stool and more withholding. When a child does not pass stool regularly and stool builds up in the rectum, liquid stool may leak around the hard stool mass and the child may develop decreased voluntary control over the anal sphincter resulting in accidents like encopresis (soiling of the underwear) and other complications.

Pearls & Alerts for Assessment

Red flags for organic disease

Consider further causes of constipation if there is delayed passage of meconium; onset <1 month of age; vomiting with abdominal pain or distension, or bilious vomiting; blood mixed into the stool; pain causing night awakenings; or weight loss.

When to refer

Referral to a subspecialist is recommended only when there is concern for organic disease or when the constipation persists despite appropriate therapy.

Causes of fecal incontinence

While fecal incontinence (including soiling and encopresis) usually is due to constipation, 20% of incontinent children actually have non-retentive fecal incontinence (defined as socially inappropriate loss of control of the bowels not caused by constipation or another medical condition). [Koppen: 2016]

Screening

No screening is recommended.

Presentations

Presentations may involve:
  • Straining in toddlers and older children, although in infants, straining and crying to pass normal, soft stool (known as dyschezia) is common and should improve once the infant has more muscle coordination
  • In toddlers and children, behaviors that reflect attempts to not pass stool, such as standing and/or crossing their legs while straining, or hiding when they need to pass stool
  • Infrequent stools for the child’s age and/or very irregular patters of stooling
  • Tearing/bleeding from the rectum (anal fissures, hematochezia)
  • Fecal soiling due to leakage around large, obstructing stool and decreased sensitivity and awareness of the presence of stool at the anus. Soiling (stool staining in the underwear) and encopresis (loss of full-size stool) are often used interchangeably and are both included in the term “fecal incontinence” used in current literature and guidelines.
  • Pebbly or bulky hard stools (can clog the toilet)
  • Withholding and/or accidents due to anxiety about painful stools
  • Onset of abdominal pain with meals, due to stimulation of the gastro-colic reflex resulting in cramping as peristalsis meets firm stool that is hard to move
  • Less commonly, vomiting or reflux

Diagnostic Criteria

According to Rome IV diagnostic criteria for the Neonate/Toddler, diagnosis must include 1 month of at least 2 of the following in infants up to 4 years of age: [Benninga: 2016]
  • Two or fewer defecations per week
  • History of excessive stool retention
  • History of painful or hard bowel movements
  • History of large-diameter stools
  • Presence of a large fecal mass in the rectum
In toilet-trained children, the following additional criteria may be used:
  • At least 1 episode/week of incontinence after the acquisition of toileting skills
  • History of large-diameter stools that may obstruct the toilet
According to Rome IV diagnostic criteria for the Child/Adolescent, diagnosis must include 2 or more of the following occurring at least once per week for a minimum of 1 month with insufficient criteria for a diagnosis of irritable bowel syndrome: [Hyams: 2016]
  • Two or fewer defecations in the toilet per week in a child whose developmental age is at least 4 years
  • At least 1 episode of fecal incontinence* per week
  • History of retentive posturing (standing or sitting with legs crossed or straight and stiff in order to avoid passing stool, or hiding and becoming red in the face while straining to hold in stool) or excessive volitional stool retention
  • History of painful or hard bowel movements
  • Presence of a large fecal mass in the rectum
  • History of large diameter stools that can obstruct the toilet
After appropriate evaluation, the symptoms cannot be fully explained by another medical condition.
*Of note, while constipation causes the majority of childhood fecal incontinence (including soiling and encopresis), 20% of incontinent children actually have non-retentive fecal incontinence (defined as socially inappropriate loss of control of the bowels not caused by constipation or another medical condition). [Koppen: 2016]

Differential Diagnosis

Differential diagnoses can include:
  • Normal stooling
  • Normal early childhood developmental phase (typical for kids ages 16-24 months)
  • Non-retentive fecal incontinence
Differential Diagnosis of Constipation in Children (AAFP), Table 4, lists recommended diagnostic evaluation for possible differential diagnoses.

Medical Conditions Causing Condition

Medical conditions that may cause constipation include:
  • Hirschsprung disease
  • Diabetes
  • Spina bifida
  • Cerebral palsy
  • Autism
  • Hypothyroidism or electrolyte disturbances
  • Developmental delays
  • Tube feeding
  • Anxiety (fear of using public restrooms, asking permission to go to bathroom at school, etc.)
  • Inadequate intake of fluid and nutrition or excessive vomiting (not enough in, not enough out)
  • Drug, supplement, or toxin effect
  • Obstruction or pseudoobstruction
  • Botulism
  • Celiac disease
  • Irritable bowel syndrome
  • Specific dietary protein allergy
  • Anatomical malformations or masses of the intestinal tract
  • Spinal cord dysfunction, tethered cord
  • Multiple endocrine neoplasia type 2B [Tabbers: 2014]
  • Sexual abuse [Philips: 2015] [: ]
Red Flags Suggesting an Organic Cause of Constipation in Children (AAFP), Table 3, presents clinical findings that may be suggestive of a diagnosis other than functional constipation.

History & Examination

Frequently, the medical home clinician can diagnose constipation based on history. The physical exam may provide supporting evidence, such as palpable stool in the abdomen or rectal vault, and lack of findings suggestive of a “surgical belly.” Labs and imaging usually are not needed to diagnose constipation.

Current & Past Medical History

General questions:
  • Was there passage of meconium after 48 hours of birth?
  • Is there a difficulty or delay in stooling that has been present at least 2 weeks?
  • What is the consistency and appearance of the stool? Communication about different stool consistencies can be made simpler using stool scales or by looking at samples or pictures that families bring to discuss. Check if there are hard, pebble-like, or fragmented stools.
  • Are any of the following present?
    • Infrequent stooling that is associated with pain
      • Is the pain associated with sense of urgency to stool, and is the pain relieved with passage of stool?
    • Sharp, cramping abdominal pain
      • Typical location is near the belly button or lower left or right side.
      • Typical timing is intermittent daytime pain, during or shortly after a meal (typically dinner), or with exercise.
    • Stool withholding or fear of passing stool
    • Stool leaking/fecal soiling (involuntary staining of the underpants, also known as encopresis) or stool accidents not appropriate for developmental age. [Hyams: 2016] Soiling is more commonly associated with constipation, whereas loss of full size stool may be associated with functional non-retentive fecal incontinence (FNRFI). [Koppen: 2016] Fecal incontinence that occurs without evidence of stool retention or slowed colonic transit time, or is in conjunction with urinary incontinence, or is associated with stress or trauma in the child’s life, should trigger the clinician to consider a diagnosis of functional nonretentive fecal incontinence.
    • Toilet clogging (large, bulky stools)
    • Dyschezia
    • Sense of incomplete bowel movements/unable to fully empty
    • Early satiety/fills up fast, sense of bloating or nausea, prefers to snack rather than have full meal
    • Irritability when no stool has passed recently
    • School absence related to constipation or abdominal pain
  • What is the toileting schedule or pattern? The Stool Diary Using Bristol Stool Form Scale (NIH) (PDF Document 147 KB) can help families record this information.
  • What is the timing and composition of meals, snacks, and fluid intake? A 3-day intake diary may be useful to review.
    • Is there excessive milk or juice intake?
    • Is there a pattern of eating small amounts throughout the day (grazing pattern of eating)?
  • Ask about frequency of exercise. For children with limited mobility, ask about time in standers or walkers.
  • Identify chronic illnesses and medical conditions, including prior procedures and surgeries. Obtain information about any prior GI studies or tests and any medical providers already consulted for this issue.
  • Identify all over-the-counter and prescription medications, fiber, and natural remedies used.

Physical Exam

Constipation is present if the history suggests constipation, and there is a palpable fecal mass on abdominal exam and/or a large amount of stool present on rectal exam. It is helpful to know that a stool ball may be present in 85% of children in the morning, so a fecal ball on rectal exam does not automatically require medical intervention.

General

Perform visual exam for fissures, hemorrhoids, fistula, tags, prolapse, or abnormal positioning and whether they are on or off the midline position. Although a routine rectal exam is not recommended to diagnose functional constipation, the exam may be needed to exclude or evaluate other conditions (e.g., Hirschsprung disease in infancy). 

Evaluate hydration status, pain status, ability to take oral fluids and medications, and mental status.

Growth Parameters

Evaluate growth curve for weight loss, short stature, or low weight for height/length or declining BMI. Failure to thrive may be an indication of Hirschsprung disease, impaction, or neurenteric problems. [Tabbers: 2014]

Skin

Check for atopic dermatitis.

HEENT/Oral

Check for aphthous ulcers, which can be indicative of inflammatory bowel disease

Abdomen

Check for bowel sounds, distension, focal or diffuse tenderness, palpable fecal mass, or surgical scars.

Extremities/Musculoskeletal

Look for overt spinal anomalies, such as abnormal sacral dimple or sinus, hair patch, or pigmentation above the gluteal cleft. Check for clubbing or joint pain.

Neurologic Exam

Evaluate sphincter tone and anal wink, consider cremasteric response. Assess gross motor control to the lower portion of the body by visualizing gait and weight bearing, for example, and assess for lower body sensation and deep tendon reflexes.

Testing

Labs and imaging studies are usually unnecessary in the outpatient setting. However, particularly if there are red flags, consider focused testing.

Laboratory Testing

Basic metabolic panel, celiac panel, thyroid-stimulating hormone, urinalysis, complete blood count, albumin, sedimentation rate, C-reactive protein, iron stores, guaiac, calcium, and potassium testing may be considered to evaluate for specific causes.

Imaging

Abdominal X-ray is not recommended as a routine test for constipation in children, nor to confirm a successful “clean-out.” Incidental finding of stool on radiography is not independently diagnostic of constipation.

Abdominal X-rays should be obtained if there is concern for bowel obstruction or perforation (2-views) or a foreign body (foreign body series). In unusual cases, studies such as barium enemas, manography, endoscopy, GI biopsies, and emptying times may be useful diagnostic tools, but these are not routinely indicated and consultation with a pediatric gastroenterologist would be advised.

Colonic transit time (CTT) may assist in differentiating between fecal incontinence that is related to constipation (in which the transit time may be slower than normal) and functional non-retentive fecal incontinence which is associated with normal CTT. CTT can be assessed via abdominal x-ray after swallowing a radio-opaque marker, or by colonic transit scintigraphy. [Koppen: 2016]

Specialty Collaborations & Other Services

Pediatric Gastroenterology (see MT providers [16])

Refer for constipation that does not respond to treatment or for concerns of other organic gastrointestinal disease.

General Pediatric Surgery (see MT providers [2])

Refer for suspected Hirschsprung disease or acute surgical abdominal concerns, such as obstruction. In very severe cases of constipation, bowel evacuation under anesthesia may be required.

Pediatric Neurosurgery (see MT providers [2])

Refer for suspected tethered cord or other spinal anomalies.

Treatment & Management

Pearls & Alerts for Treatment & Management

Most recommended medication for maintenance therapy

The most highly recommended medication for maintenance therapy for pediatric functional constipation is polyethylene glycol (PEG). Lactulose, milk of magnesia, mineral oil, and stimulant laxatives can be added or used as second-line therapies. [Tabbers: 2014] While current guidelines support use of lactulose over the other second-line therapies, a 2016 Cochrane review found it inferior to mineral oil (liquid paraffin) or milk of magnesia. [Gordon: 2016]

Maintenance therapy

Polyethylene glycol (PEG) and lactulose are considered the safest medications for daily maintenance therapy in children. [Tabbers: 2014] Maintenance therapy should be continued for several months and then gradually discontinued with monitoring of stools to make sure the tapering is tolerated. [Tabbers: 2014]

Clean-outs before maintenance therapy

Children with moderate to severe constipation typically need a “clean-out” prior to initiating maintenance therapy.

Thickeners and PEG

Starch- and xanthan gum-based thickeners are used to increase the density of fluids to reduce the risk of aspiration for children with swallowing dysfunction. Recent research suggests that interactions between starch-based thickeners and PEG may result in inconsistent thickening and thus reduce their effectiveness. To date, xanthan gum-based thickeners do not seem to be affected by PEG. [Carlisle: 2016]

Offsetting costs of diapers for older children

Diapers are a large health care expense. Generally, Medicaid will cover the cost of diapers for the incontinent child after age 3 through a home care company with a clinician’s prescription and letter of medical necessity. Less frequently, private payers can be convinced to do this.

How should common problems be managed differently in children with Constipation?

Over the Counter Medications

The cost of laxatives adds up quickly. If possible, select medications that the family’s insurance will cover; otherwise, suggest generics (store brands), coupons, or online shopping to compare prices.

Common Complaints

Children often indicate the area around their umbilicus when asked to locate their abdominal pain related to constipation. When appropriate, reassure parents that their child can continue to participate in activities and attend school despite having occasional abdominal pain.

Systems

Gastro-Intestinal & Bowel Function

Basic Algorithm of Assessment & Management of Pediatric Constipation
This Basic Algorithm of Assessment & Management of Pediatric Constipation provides a clinical care guide that begins with the initial signs of constipation and ends with follow-up after successful treatment. [Koppen: 2015]

Educational resources for parents may include:
Infancy
A common time for infants to become constipated is during the introduction of solid foods and cereals to the diet. Infants may express more irritability or arch their back and cry when passing hard stool. Clinicians should provide education about normal stooling patterns in infants and manage constipation when it arises. There is insufficient evidence to routinely recommend use of a probiotic or hydrolyzed formula as first-line treatments of constipation in infants; however, in infants who do not respond to laxative therapy, a 2- to 4-week trial of a hypoallergenic formula (without cow’s milk protein) may be considered. For breastfed infants, a maternal avoidance diet of cow’s milk protein could alternatively be considered.

Toilet Training
Constipation occurs more frequently in children who are toilet training. Painful stooling can lead to irritability or anxiety in children and increased reluctance to use the toilet. Clinicians should explain to parents that the development of continence of urine and of stool often do not happen simultaneously, and fecal incontinence occurs from involuntary overflow of stool and not from voluntary defiance. Clinicians can instruct parents to:
  • Ensure easy access to the potty or toilet and comfort in getting on and off and while sitting.
  • Provide supportive seating. The child should be able to rest his or her feet on a stool or the floor. Handles can provide additional support.
  • Provide adequate time to pass stool. Many children will have better success with passing stool if they regularly take advantage of the gastro-colic reflex after meals.
  • Gently encourage efforts to use the potty, and avoiding reprimanding or shaming children when they have accidents. Use of small rewards like stickers can be helpful. Keeping a stool diary can be motivating as well as informative.
Older Children
Older children and adolescents may develop constipation when they attend school or are away from home. Many children feel anxious or embarrassed about using unfamiliar bathrooms to pass stool. In school, limited time and access to the bathroom makes it harder to relax and pass stool. This can result in the painful and retentive cycle of constipation described above. Parents can help children in this situation by discussing and planning ahead for bowel movements outside the home, and normalizing bodily functions to reduce any shame the child feels about stooling.

Setting a schedule to sit on the toilet for 5-10 minutes after meals, and possibly after school, may help children form good bowel habits. This time should be relaxed and not rushed. The child should be able to sit comfortably on the toilet with feet on the ground or on a stool to facilitate good positioning. Keeping a bowel diary and using incentives to reward compliance with the stool schedule may be motivating to older children as well as for younger kids who are potty training. These techniques help children with constipation but also can be utilized for treatment of functional non-retentive fecal incontinence. [Koppen: 2016]

Prevention
Although there is little supporting evidence, commonly given advice for caregivers to prevent constipation is to ensure healthy eating habits and diet, regular exercise, adequate fluid intake, and relaxed toileting, particularly after larger meals.

Grazing, particularly on low-fiber foods, may increase the risk of constipation because it 1) decreases the size of regular meals and the resulting bolus of food that should propel stool through the gut and 2) reduces the gastro-colic reflex.

Healthy eating habits and diet. A healthy diet helps ensure adequate nutrition and fiber intake and may help prevent constipation. A healthy diet includes at least 5 servings of fruits and vegetables daily in addition to peas, nuts, beans, and fiber-rich cereals and breads (not the same as “whole grain.”) Examples of particularly high-fiber foods include prunes, apricots, plums, raisins, raw tomatoes, peas, beans, broccoli, and sweet potatoes. Low-fiber or constipating foods include rice, cooked carrots, dairy products, bananas, and cereals or breads that are not high in fiber. [Healthy: 2015] Minimal recommended daily grams of dietary fiber can be estimated using the child’s age plus 5; however, newer recommendations are about 14g of fiber for every 1,000 calories in the diet. More general daily fiber recommendations are:
  • 1 to 3 year olds - 19 grams
  • 4 to 8 year olds - 25 grams
  • 9- to 18-year-old girls - 26 grams
  • 9- to 13-year-old boys - 31 grams
  • 14- to 18-year-old boys - 38 grams
For children >1 year old who are formula dependent, prescribe a formula with fiber unless it is not available or tolerated. Choose My Plate (USDA) offers personalized eating plans for families and interactive tools to help plan and assess food choices.

Recommend that children exercise daily for at least an hour. While there is lack of high-quality evidence about using exercise as treatment for constipation, children who exercise regularly are at decreased risk for constipation. [Koppen: 2015] For children with restricted mobility, encourage time spent in upright positioning, such as in a stander or walker; there is very limited evidence that this positioning, which uses gravity, may help decrease pain associated with passing stools in children with cerebral palsy. [Rivi: 2014]

Fluid intake (especially water): In the US, there are no commonly accepted recommendations for daily water intake for children. [Healthy: 2016] An Australian resource recommends: 1.2-1.5 liters (around 5-6 cups) daily of water for children ages 4-13. [HealthyKids: 2015] Some clinicians use the Holliday-Segar method to estimate daily fluid requirements for a child: [Meyers: 2009] 

Holliday-Segar method for calculating daily fluid requirements:
  • 100 ml/kg for the 1st 10 kg of weight
  • 50 ml/kg for the 2nd 10 kg of weight
  • 20 ml/kg for the remaining weight
Holliday-Segar adaptation to calculate hourly maintenance fluids (useful for kids who are on continuous tube feeds):
  • 100 ml/kg/24-hours - 4 ml/kg/hr for the 1st 10 kg
  • 50 ml/kg/24-hours - 2 ml/kg/hr for the 2nd 10 kg
  • 20 ml/kg/24-hours - 1 ml/kg/hr for the remainder
Discuss the benefits of relaxation. Ensure that children have regular, unrushed time on the toilet, ideally at least 5 minutes after meals. [Koppen: 2015] Increasing fluid intake leads to increased urination, which can help with anal relaxation. Sitting in a warm tub may be helpful, too. Deep breathing and conscious relaxation of the muscles involved in stool elimination can also help a child to relax; however, there is not sufficient evidence to recommend using biofeedback or behavioral therapies for routine treatment of children with functional constipation. [Tabbers: 2014]

Further information for clinicians may include:

Specialty Collaborations & Other Services

General Counseling Services (see MT providers [146])

A referral may be helpful to assist with behavioral concerns, non-pharmaceutical management of chronic pain, and anxiety, which may be contributing to constipation.

Pharmacy & Medications

In addition to dietary and lifestyle changes, over-the-counter and prescription laxatives can prevent and relieve constipation. Laxatives work by softening the stool and helping it to move more quickly through the intestine. Types of laxatives and dosing guidelines by age for clean-out and treatment are described below. Different laxative types include bulking agents (fiber), lubricating and emollient agents, osmotic and hyperosmolar agents, stimulating agents, and combined agents. Stimulant laxatives are not recommended for long-term use; however, when necessary, longer-term use of polyethylene glycol, mineral oil, magnesium hydroxide, and lactulose may be considered.  [Borowitz: 2016]

Based on current guidelines, the most highly recommended medications for maintenance therapy for functional constipation are polyethylene glycol and lactulose, in that order. Milk of magnesia, mineral oil, and stimulant laxatives can be added or used as second-line therapies. [Tabbers: 2014] However the data supporting use of laxatives other than PEG are not as clear; a 2016 Cochrane review cited limited evidence for use of mineral oil or lactulose as second line treatments to PEG. Maintenance therapy should be continued for several months and then gradually discontinued as tolerated. [Tabbers: 2014] There is not sufficient evidence to support the widespread myth that laxatives cause physical dependency; although, constipation may recur in some people once the laxative is discontinued.

Polyethylene Glycol (PEG) 3350 over-the-counter oral laxative (MiraLAX) has been added to the Potential Signals of Serious Risks List (FDA). The FDA decided that no action is necessary at this time based on available information.

Oral Osmotic Laxatives
Osmotic laxatives cause the intestinal tract to hold more fluid. Side effects may include gas, bloating, diarrhea, nausea, cramping, and thirst.

Polyethylene Glycol 3350 (e.g., PEG 3350, MiraLAX, GlycoLax)
  • For clean-out of fecal impaction phase: 1-1.5 g/kg/day x 3-6 days, maximum 100 g/day
  • For maintenance phase: 0.2-0.8 g/kg/day (can be divided in 1-3 doses), maximum 17 g/day, often continued for several months
  • H2O ratio: 1 teaspoon to 2.5 oz. liquid; 17 g to 4-8 oz. liquid or 5 g = 1 teaspoon
    • 17 g = 1 capful = 1 heaping tablespoon
    • Do not count the PEG fluid volume in the child’s total daily maintenance fluid volume.
Lactulose (e.g., Enulose, Kristalose) - a synthetic sugar
  • Liquid (10 g/15 mL sol) or packets: 1-2 g/kg 1-2 times daily, max 40 g, in divided doses [Tabbers: 2014]
Magnesium hydroxide (e.g., Phillips Milk of Magnesia, PediaLax chewables) - a saline laxative
  • Phillips Milk of Magnesia original strength 400 mg/5 mL suspension  [Tabbers: 2014]
    • 2-5 years: 0.4-0.12 g/day or 5-15 mL/day in 1-2 divided doses
    • 6-11 years: 1.2-2.4 g/day or 15-30 mL/day in 1-2 divided doses
    • ≥12 years: 2.4-4.8 g/day or 30-60 mL/day in 1-2 divided doses 
  • PediaLax chewables
    • 2-5 years: 1-3 tablets
    • 6-11 years: 3-6 tablets
Magnesium citrate (e.g., Citroma, GoodSense) - a saline laxative
  • Citroma or GoodSense (1.75 g/30 mL) solution
    • 2-6 years: 3.5-5.25 mg (60-90 mL) daily
    • 6-12 years: 5.25-12.25 mg (90-210 mL) daily
    • >12 years: 12.25- 17.5 mg (195-300 mL) in single or divided doses
  • Citroma or GoodSense 100 mg tablets
    • >12 years: 200-400 mg (2-4 tablets) in single or divided doses
Lubricant Laxatives
This type of laxative surround the outside of the stool with a slippery coating to enable smoother passage of stool and to keep water in the stool.

Mineral oil (e.g., Kondremol) [Tabbers: 2014]
  • 2-11 years: 30-60 mL daily
  • ≥12 years: 60-150 mL of plain mineral oil daily given as a single dose
Oral Stool Softeners
This type of laxative helps mix moisture into the stool to make it softer and reduce straining. Stool softeners do not trigger more frequent stool passage.

Sodium docusate (e.g., Colace, PediaLax Liquid Stool Softener)
  • In liquid (50 mg/15 mL), syrup (60 mg/15 mL), or capsules (50, 100, 240, and 250 mg)
    • 2-11 years: 50-150 mg/day (single or divided)
    • ≥12 years: 50-360 mg/day (single or divided)
  • PediaLax [Tabbers: 2014]
    • 2-11 years: 1-3 tablespoons mixed with milk or juice
Oral Stimulant Laxatives
The harshest type of laxative, a stimulant laxative, causes increased contractions of the gut to help move stool out within several hours. Use should be limited to a few days at most.

Senna/sennosides (e.g., ExLax, Little Tummies, Senokot) - in tablets (8.6 mg, 15 mg, and 25 mg doses), chewables (15 mg tablets), liquid and syrup (8.8 mg/5 mL)  [Tabbers: 2014]
  • 2-5 years: 2.5-5 mg/1-2 times daily
  • 6-12 years: 7.5-10 mg/day
  • >12 years: 15-20 mg/day
Senna pod extract (e.g., Fletchers) (167 mg/5 mL) (Dosing is not equivalent to other senna products.)
  • 2-5 years: 167-333 mg (5-10 mL) daily
  • 6-15 years: 333-500 mg (10-15 mL) daily or divided
Senna leaf extract  [Tabbers: 2014]
  • 2-6 years: 166.5-666 mg/day
  • 6-12 years: 333-999 mg/day
Bisacodyl (e.g., Biscolax, Dulcolax, Correctol in 5 mg tablets) [Tabbers: 2014]
  • 3-10 years: 5 mg/day
  • >10 years: 5-10 mg/day
Rectal Suppositories
These help evacuate the rectum by coating the stool and making it slippery. Stool typically is evacuated within an hour. Suppositories are not routinely advised for daily use.

Glycerin (e.g., Pedia-Lax, Fleets) - solid suppository in 1, 1.2, 2, and 2.8 mg sizes or liquid suppository (i.e., liquid delivered via rectal applicator)
  • Solid suppository
    • <4 months: 0.5 mg (1/2 pediatric suppository)
    • 4 months--5 years: 1 mg (1 pediatric suppository)
    • 6 years-adolescence: 2 mg (1 adult suppository)
  • Pedia-Lax liquid glycerin suppository (2.8 mg/2.25 mL bottle)
    • 2-5 years: 1 suppository given rectally x 1 via rectal applicator
Bisacodyl (e.g., Biscolax 10 mg suppository) [Tabbers: 2014]
  • 1-2 years: 1/2 suppository
  • 2-11 years: 1/2-1 suppository
  • ≥12 years: 1 suppository
Enemas
Enemas flush out the rectum and act more quickly than oral laxatives. Side effects can include incomplete evacuation of the fluid, which can lead to discomfort, distension, or electrolyte imbalances. There are other do-it-yourself and commercial enemas, but due to the risks, only 2 selected osmotic enemas are presented here.

Saline enema (e.g., Pedia-Lax, Fleet Saline) - The FDA announced in 2014 that using these more than once daily can result in serious harm to the kidneys and should NEVER be given to children under 2 years of age. [Tabbers: 2014] [U.S.: 2016]
  • Pedia-Lax (monobasic sodium phosphate 9.5 g and dibasic sodium phosphate 3.5 g/66 mL bottle)
    • 2-4 years: 1/2 bottle
    • 5-11 years: 1 bottle rectally x 1
  • Adult saline enema (Fleets - 19 g monobasic sodium phosphate monohydrate and 7 g dibasic sodium phosphate heptahydrate/188 mL bottle)
    • ≥12 years: 1 bottle
Mineral oil enema [Tabbers: 2014]
  • 2-11 years: 30-60 mL daily
  • ≥12 years: 60-150 mL daily
Sodium docusate enema (e.g., DocuSol Kids-100 mg/5 mL, DocuSol Mini and Enemeez Mini-283 mg/~5 mL tube)
  • 2-12 years: 100 mg (1 DocuSol Kids tube)
  • ≥12 years: 283 mg (1 DocuSol or Enemeez Mini tube)
  • Alternative dosing  [Tabbers: 2014]
    • <6 years: 60 mL daily
    • >6 years: 120 mL daily
Bisacodyl enema (e.g., Fleet Bisacodyl (10 mg/37 mL container) [Tabbers: 2014]
  • 2-10 years: 5 mg (1/2 enema) daily
  • >10 years: 5-10 mg (1/2-1 enema) daily
Other Oral Medications
Other oral medications are occasionally used to treat adult chronic constipation, such as lubiprostone (Amitiza), linaclotide (Linzess, Constella), prucalopride (Reselor), tegaserod (Zelnorm), and almivopan (Entereg). These medications SHOULD NOT be used in the primary care management of pediatric constipation.

Fiber/Oral Bulk-Forming Laxatives
Fiber supplements have not been demonstrated to be effective in the treatment of pediatric constipation, limited evidence shows that additional fiber improves constipation and may help in prevention. [Tabbers: 2014] Fiber is the non-digestible carbohydrate portion of many foods. Both soluble and insoluble fibers are important to digestive tract health. 

Insoluble fiber helps “bulk” the stools and promotes normal contractions and motility so stools pass more quickly through the GI tract. Insoluble fiber food sources include wheat bran, whole grains (cereal, pasta, and bread), seeds, nuts, leafy greens, broccoli, and the skins of many fruits and root vegetables. Other sources are as follows:
  • Methylcellulose (Citrucel) contains insoluble semi-synthetic fiber. It is non-fermentable, so not as likely as fermentable fiber to produce gas.
  • Polycarbophil (FiberCon) contains insoluble synthetic fiber and is also non-fermentable.
  • Fiber gummies can contain either or both soluble and insoluble types of fiber.
Soluble fiber slows digestion by attracting water and forming a gel, which allows time in the GI tract for nutrients to be absorbed, helps regulate blood sugar, and potentially reduces LDL cholesterol. In general, soluble fiber is less helpful than insoluble fiber in fighting constipation. Soluble fiber food sources include oatmeal, lentils, seeds and beans, psyllium, chicory and inulin, and certain berries. Other sources are as follows:
  • Wheat dextrin (Benefiber) contains soluble fiber, which is fermentable in the gut.
  • Psyllium (Metamucil) contains mostly soluble fiber, which is partially fermentable and still may cause gas.
  • Barley malt extract (Maltsupex) contains soluble fiber.
Use of fiber supplements can lead to bloating, gas, cramping, and constipation particularly if not taken with adequate water. Side effects are reduced or eliminated by starting with small amounts and gradually working up to the dose and frequency goal. As a guideline, increase the dose gradually to 1/2 or 1 rounded teaspoon, packet, or wafer in 4 oz. of water 1-3 times per day. [Drugs.com: 2016] Long-term use of fiber is fine. If fiber is not tolerated, or not effective due to underlying medical conditions, then other medications can be considered. For more information about adding fiber to the diet, see Dietary Fiber (IFFGD) and Fiber Recommendations for Kids (About.com).

Specialty Collaborations & Other Services

Pharmacies / Prescriptions (see MT providers [26])

Refer for questions about medication use and administration.

Complementary & Alternative Medicine

The following therapies may have some benefit as adjuncts but are usually not effective in managing constipation for the majority of pediatric patients.

Acupuncture and biofeedback are gaining some supporting evidence for use in adults with constipation, and there is emerging evidence for biofeedback use in adults with dys-synergic defecation. [Broide: 2001] [Rao: 2015] However, neither of these approaches is currently recommended for routine treatment of childhood constipation due to lack of supporting evidence in this population. Similarly, there is lack of evidence for use of behavioral therapy to treat children with constipation.

Current clinical practice guidelines do NOT recommend use of natural remedies or alternative therapies for treatment of functional constipation in large part because they often lack safety studies and may be unhealthy or dangerous, especially in high doses. Despite this, these are some remedies that caregivers may be using:
  • Lemon juice stimulates contractility.
  • Molasses by mouth can have stimulating effects. Not recommended for routine treatment of constipation. (A hospital in Utah no longer performs or recommends milk and molasses enemas due to a sentinel event.)
  • Aloe is thought to help with occasional constipation, yet it can be unsafe at high doses and therefore should not be used for routine treatment of constipation. [WebMD: 2015]
  • Probiotics generally do not have sufficient evidence to be used in treatment or prevention of chronic constipation; however, they are beneficial to overall intestinal health. [Thomas: 2010]
  • Prebiotics are non-digestible food ingredients that help propagate healthy gut bacteria. All prebiotics are fiber, but not all fibers are prebiotic. Examples of prebiotics include inulin, wheat dextrin, and polydextrose. [Slavin: 2013]
  • A 2- to 4-week trial of avoidance of cow’s milk protein (CMP) may be indicated in the child with intractable constipation that does not respond to laxatives.  [Tabbers: 2014] Since CMP intolerance or allergy is not typically IgE mediated, blood levels, patch or skin prick test are not routinely recommended for diagnosis.   [Vandenplas: 2015] For breastfed babies, a maternal elimination diet may be trialed.

Issues Related to Constipation

Gastro-Intestinal & Bowel Function

Bowel Management in Children with Spina Bifida

Ask the Specialist

When do children need admission to the hospital for constipation clean-outs?

With persistence of the parents and detailed education and encouragement from the primary care provider, almost all children with constipation, including children with developmental difficulties, can do colon or bowel clean-outs at home. Reasons to send a patient to the emergency room may include suspected bowel obstruction (bilious emesis, signs of obstruction on abdominal X-ray, severe abdominal distention) or inability to tolerate any kind of oral intake.

When do primary care physicians need to refer children with constipation to the pediatric gastroenterology clinic?

Most children with constipation can be successfully managed by primary care physicians. Reasons to refer to the pediatric gastroenterology clinic include presence of alarming signs or symptoms suggestive of organic disease, relapse of symptoms after initial successful treatment, and no improvement after appropriate treatment.

Is a “stool ball” an indication for manual digital evacuation?

The only true indication for manual digital evacuation is bowel obstruction or suspected bowel obstruction due to impacted stool. Most fecal impactions can be disimpacted with oral or rectal medication. A stool ball may be present in 85% of children in the morning and is not an indication for manual digital evacuation.

Resources for Clinicians

On the Web

Pediatric Constipation and Referral Guidelines (Dayton Children’s Hospital) (PDF Document 195 KB)
Guidance for primary care and emergency providers regarding evaluation and treatment of pediatric patients with symptoms of constipation.

Helpful Articles

Berger MY, Tabbers MM, Kurver MJ, Boluyt N, Benninga MA.
Value of abdominal radiography, colonic transit time, and rectal ultrasound scanning in the diagnosis of idiopathic constipation in children: a systematic review.
J Pediatr. 2012;161(1):44-50.e1-2. PubMed abstract / Full Text

Gordon M, MacDonald JK, Parker CE, Akobeng AK, Thomas AG.
Osmotic and stimulant laxatives for the management of childhood constipation.
Cochrane Database Syst Rev. 2016(8):CD009118. PubMed abstract

Koppen IJ, von Gontard A, Chase J, Cooper CS, Rittig CS, Bauer SB, Homsy Y, Yang SS, Benninga MA.
Management of functional nonretentive fecal incontinence in children: Recommendations from the International Children's Continence Society.
J Pediatr Urol. 2016;12(1):56-64. PubMed abstract

Nurko S, Zimmerman LA.
Evaluation and treatment of constipation in children and adolescents.
Am Fam Physician. 2014;90(2):82-90. PubMed abstract

Clinical Tools

Assessment Tools/Scales

Bristol Stool Form Scale (PDF Document 383 KB)
Images of 7 stool types, created to facilitate better communication among families and clinicians about bowel movements; developed by the Bristol Royal Infirmary.

Lane Scale
The Bristol scale adapted for children by decreasing the number of stool categories from 7 to 5; Lane, M, et al.

Amsterdam Infant Stool Scale
A stool scale for premature and term infants, scroll to page 3 for chart; accessible for a fee.

Questionnaires/Diaries/Data Tools

Stool Diary Using Bristol Stool Form Scale (NIH) (PDF Document 147 KB)
Printable record of stool habits for 1 week; originally from Lewis SJ, Heaton KW, Scandinavian Journal of Gastroenterology - reproduced by the National Institutes of Health.

Food Record (University of Rochester) (PDF Document 151 KB)
A 3-day food record with instructions for parents.

Patient Education & Instructions

Understanding and Treating Constipation in Children Video
An 8-minute video that helps parents and other caregivers understand constipation and what can be done to remedy it; Intermountain Healthcare.

The Poo in You - Constipation and Encopresis Video (Children's Hospital Colorado)
Excellent 5-minute video about why soiling accidents occur and what can be done to make them stop happening. Includes simple information about the digestive process, role of colon, and medicines that may help with constipation and resulting encopresis.

Infant Constipation (Nationwide Children's Hospital)
Information about signs of constipation in infants under 1 year of age and indications for when to call your doctor.

Let’s Talk About Constipation (Intermountain Healthcare)
One-page handout explaining childhood constipation.

Let's Talk About... Fleet Enemas (Spanish & English)
Handout for caregivers on how to give enemas to children; Intermountain Healthcare.

Let's Talk About... Constipation in a Child: Bowel Clean Out (Spanish & English)
Guide for caregivers on bowel clean-out and daily care for constipation at home; Intermountain Healthcare.

Let's Talk About... Rectal Suppository (Spanish & English)
One-page guide for caregivers about rectal suppositories for children; Intermountain Healthcare.

Resources for Patients & Families

Constipation Management and Prevention of Constipation in Children

Information on the Web

About Kids and Teens GI Health (IFFGD)
Reliable digestive health knowledge, support, and assistance about functional gastrointestinal and motility disorders; International Foundation for Functional Gastrointestinal Disorders.

Baby's First Days: Bowel Movements & Urination (AAP)
Important points about first bowel movements; American Academy of Pediatrics.

How Do I Know If My Child Is Constipated? (AAP)
Information about bowel patterns, and signs, treatment, and prevention of constipation; American Academy of Pediatrics.

Dietary Fiber (IFFGD)
Information about different kinds of fiber, how to incorporate fiber into the diet gradually, and serving sizes to help prevent constipation; International Foundation for Functional Gastrointestinal Disorders.

Studies/Registries

Pediatric Constipation (clinicaltrials.gov)
Comprehensive list of research studies related to pediatric constipation; National Institutes of Health.

Services for Patients & Families in Montana (MT)

For services not listed above, browse our Services categories or search our database.

* number of provider listings may vary by how states categorize services, whether providers are listed by organization or individual, how services are organized in the state, and other factors; Nationwide (NW) providers are generally limited to web-based services, provider locator services, and organizations that serve children from across the nation.

Authors & Reviewers

Initial publication: January 2017
Current Authors and Reviewers:
Senior Author: Jennifer Goldman-Luthy, MD, MRP, FAAP
Reviewers: Ramakrishna Mutyala, MD
Mark Deneau, MD
Chuck Norlin, MD

Bibliography

Missing citation with id: 3416

Benninga MA, Faure C, Hyman PE, St James Roberts I, Schechter NL, Nurko S.
Childhood Functional Gastrointestinal Disorders: Neonate/Toddler.
Gastroenterology. 2016. PubMed abstract

Berger MY, Tabbers MM, Kurver MJ, Boluyt N, Benninga MA.
Value of abdominal radiography, colonic transit time, and rectal ultrasound scanning in the diagnosis of idiopathic constipation in children: a systematic review.
J Pediatr. 2012;161(1):44-50.e1-2. PubMed abstract / Full Text

Borowitz SM.
Pediatric Constipation Medication.
Medscape; (2016) http://emedicine.medscape.com/article/928185-medication. Accessed on 08/30/2016.
Information about various medications used to treat constipation in children from medical experts. Medications include osmotic laxatives, lubricants, stimulant laxatives, stool softeners, and stool softeners in combination with stimulants.

Broide E, Pintov S, Portnoy S, Barg J, Klinowski E, Scapa E.
Effectiveness of acupuncture for treatment of childhood constipation.
Dig Dis Sci. 2001;46(6):1270-5. PubMed abstract

Carlisle BJ, Craft G, Harmon JP, Ilkevitch A, Nicoghosian J, Sheyner I, Stewart JT.
PEG and Thickeners: A Critical Interaction Between Polyethylene Glycol Laxative and Starch-Based Thickeners.
J Am Med Dir Assoc. 2016;17(9):860-1. PubMed abstract

Drugs.com.
Bulk-Forming Laxatives.
Drugs.com; (2016) http://www.drugs.com/monograph/bulk-forming-laxatives.html. Accessed on 8/30/2016.
Information about fiber laxatives with doses and warnings.

Gordon M, MacDonald JK, Parker CE, Akobeng AK, Thomas AG.
Osmotic and stimulant laxatives for the management of childhood constipation.
Cochrane Database Syst Rev. 2016(8):CD009118. PubMed abstract

Healthy Children Magazine.
Constipation.
American Academy of Pediatrics; (2015) http://www.healthychildren.org/English/health-issues/conditions/abdomi.... Accessed on 8/30/2016.
Information about how to know if your child is constipated and what to do.

Healthy Children Magazine.
Childhood Nutrition.
American Academy of Pediatrics; (2016) http://www.healthychildren.org/English/healthy-living/nutrition/Pages/.... Accessed on 8/30/2016.
Information about what to eat and how much; healthychildren.org is from the American Academy of Pediatrics.

HealthyKids.
Choose Water as a Drink.
Department of Health - New South Wales (NSW); (2015) http://www.healthykids.nsw.gov.au/downloads/file/kidsteens/HealthyKids.... Accessed on 8/30/2016.
Information about how much water children should drink.

Hyams JS, Di Lorenzo C, Saps M, Shulman RJ, Staiano A, van Tilburg M.
Functional Disorders: Children and Adolescents.
Gastroenterology. 2016. PubMed abstract

International Foundation for Functional Gastrointestinal Disorders.
Stool Form Guide.
International Foundation for Functional Gastrointestinal Disorders; (2016) http://www.aboutconstipation.org/site/treatment/stool-form-guide. Accessed on 8/30/2016.
Bristol Stool Form Guide with types, images, and descriptions.

Koppen IJ, Lammers LA, Benninga MA, Tabbers MM.
Management of Functional Constipation in Children: Therapy in Practice.
Paediatr Drugs. 2015;Oct. PubMed abstract / Full Text

Koppen IJ, von Gontard A, Chase J, Cooper CS, Rittig CS, Bauer SB, Homsy Y, Yang SS, Benninga MA.
Management of functional nonretentive fecal incontinence in children: Recommendations from the International Children's Continence Society.
J Pediatr Urol. 2016;12(1):56-64. PubMed abstract

Levy J, Volpert D.
Introduction to Constipation in Children.
International Foundation for Functional Gastrointestinal Disorders; (2016) http://www.aboutkidsgi.org/site/lower-gi-disorders/childhood-defecatio.... Accessed on 8/30/2016.
Provides a definition, prevalence, and information about chronic constipation.

Meyers RS.
Pediatric fluid and electrolyte therapy.
J Pediatr Pharmacol Ther. 2009;14(4):204-11. PubMed abstract / Full Text

Mugie SM, Benninga MA, Di Lorenzo C.
Epidemiology of constipation in children and adults: a systematic review.
Best Pract Res Clin Gastroenterol. 2011;25(1):3-18. PubMed abstract

Nurko S, Zimmerman LA.
Evaluation and treatment of constipation in children and adolescents.
Am Fam Physician. 2014;90(2):82-90. PubMed abstract

Peeters B, Benninga MA, Hennekam RC.
Childhood constipation; an overview of genetic studies and associated syndromes.
Best Pract Res Clin Gastroenterol. 2011;25(1):73-88. PubMed abstract

Philips EM, Peeters B, Teeuw AH, Leenders AG, Boluyt N, Brilleslijper-Kater SN, Benninga MA.
Stressful Life Events in Children With Functional Defecation Disorders.
J Pediatr Gastroenterol Nutr. 2015;61(4):384-92. PubMed abstract

Rao SS, Benninga MA, Bharucha AE, Chiarioni G, Di Lorenzo C, Whitehead WE.
ANMS-ESNM position paper and consensus guidelines on biofeedback therapy for anorectal disorders.
Neurogastroenterol Motil. 2015;27(5):594-609. PubMed abstract / Full Text

Rivi E1, Filippi M, Fornasari E, Mascia MT, Ferrari A, Costi S.
Effectiveness of standing frame on constipation in children with cerebral palsy: a single-subject study.
Occup Ther Int. . 2014. PubMed abstract

Slavin J.
Fiber and prebiotics: mechanisms and health benefits.
Nutrients. 2013;5(4):1417-35. PubMed abstract / Full Text

Tabbers MM, DiLorenzo C, Berger MY, Faure C, Langendam MW, Nurko S, Staiano A, Vandenplas Y, Benninga MA.
Evaluation and treatment of functional constipation in infants and children: evidence-based recommendations from ESPGHAN and NASPGHAN.
J Pediatr Gastroenterol Nutr. 2014;58(2):258-74. PubMed abstract / Full Text

Thomas DW, Greer FR.
Probiotics and prebiotics in pediatrics.
Pediatrics. 2010;126(6):1217-31. PubMed abstract / Full Text

U.S. Food and Drug Administration.
Possible harm from exceeding recommended dose of over-the-counter sodium phosphate products to treat constipation.
U.S. Food and Drug Administration; (2016) http://www.fda.gov/drugs/drugsafety/ucm380757.htm. Accessed on 08/30/2016.
Lists warnings, bulletins, and updates.

Vandenplas Y, Alarcon P, Alliet P, De Greef E, De Ronne N, Hoffman I, Van Winckel M, Hauser B.
Algorithms for managing infant constipation, colic, regurgitation and cow's milk allergy in formula-fed infants.
Acta Paediatr. 2015;104(5):449-57. PubMed abstract

Varier R, Harnsberger J.
Constipation Care Plan for Primary Children's Medical Center.
Primary Children's Hospital. 04/08/2013.

WebMD.
Aloe.
WebMD; (2015) http://www.webmd.com/vitamins-supplements/ingredientmono-607-aloe.aspx.... Accessed on 8/30/2016.
Information and warnings about use of aloe.

van Ginkel R, Reitsma JB, Büller HA, van Wijk MP, Taminiau JA, Benninga MA.
Childhood constipation: longitudinal follow-up beyond puberty.
Gastroenterology. 2003;125(2):357-63. PubMed abstract / Full Text