II. Epidemiology

  1. Responsible for 3% of pediatric primary care visits (and 10-25% of pediatric gastroenterology visits)
  2. Overall Prevalence may be as high as 30% of children and teens worldwide
  3. Age of onset
    1. Median onset age 2.3 years
    2. Onset often coincides with transition to solid foods, Toilet Training or school entry

III. Definitions

  1. Constipation in Children
    1. Decrease in stool frequency (<3 stools per week)
    2. Decreased fluidity of Bowel Movements (most stools are hard, pebble-like or scybalous)
    3. Pain or excessive straining on stooling

IV. Physiology

  1. See Defecation
  2. Mean stool frequency varies by age
    1. Breastfed infants under age 3 months: 2.9 stools/day (healthy Breastfed infants may not have stool for days)
    2. Formula-fed infants under age 3 months: 2 stools/day
    3. Age 6 to 12 months: 1.8 stools per day
    4. Age 1 to 3 years: 1.4 stools per day
    5. Age over 3 years: 1.0 stools per day
  3. References
    1. Baker (1999) J Pediatr Gastroenterol Nutr 29:612-26 [PubMed]

V. Pathophysiology

  1. Stool Withholding
    1. Occurs when stooling becomes painful (young children) or learned behavior (teens)
    2. Retained stools in turn become more firm, harder to pass, as the colon resorbs water from stool
    3. Child fights urge to defecate by contracting anal sphincter and gluteal Muscles
    4. Ultimately, fecal retention occurs, dilating Rectum and reducing stool urge
    5. Stool accumulates, resulting in Abdominal Distention, pain, Nausea, and decreased oral intake

VI. Causes

  1. See Constipation Causes in Children
  2. See Constipation Causes in Newborns
  3. Functional Constipation (non-organic) causes are most common (95% of cases)
    1. Often caused by stool witholding due to painful Bowel Movements

VII. History

  1. Stool characteristics
    1. Time of passage of first meconium
      1. Delayed >48 hours in Hirschsprung's Disease
    2. Age of onset of stool problems
      1. Neonatal (especially under age 1 month) onset suggests congenital cause
      2. Onset under age 1 year suggests dietary cause
      3. Onset after 18 months suggests behavioral cause (Functional Constipation)
    3. Timing of stool problems
      1. Acute Constipation suggests organic cause
      2. Chronic Constipation suggests functional cause
      3. Older children will often have Colicky Abdominal Pain after eating in Functional Constipation
    4. Frequency of stools
      1. Infants without stool in 2 days or even up to 7 days may be normal pattern
        1. Breast fed infants will often have stool frequency drop to every few days
      2. Normal stool frequency may suggest Irritable Bowel Syndrome
    5. Size of Bowel Movements
      1. Large caliber stools suggests functional cause (especially stool witholding)
      2. Small caliber stools suggest Hirschsprung's Disease
  2. Associated symptoms and conditions
    1. Abdominal Pain
      1. Relieved with Defecation may suggest Irritable Bowel Syndrome
      2. Exclude other causes of Abdominal Pain
    2. Presence of pain with Defecation (Dyschezia)
      1. Consider Anal Fissures (May also present with blood on stool)
    3. Presence of Rectal Prolapse
    4. Hematochezia (Bright Red Blood Per Rectum)
      1. See Red Flags below
      2. Consider Anal Fissures (related to passage of hard stools)
      3. Consider Food Allergy (Cow's Milk Allergy)
      4. Consider Hirschprung's Disease
    5. Stool Withholding (see pathophysiology above)
    6. Systemic symptoms (see red flags below)
      1. Suggests organic cause
  3. Bowel control
    1. Age of Toilet Training
    2. Presence of Encopresis or fecal soiling (suggests Fecal Impaction)
    3. Presence of Enuresis
    4. Stool Withholding (see below)
  4. Prior and current management (medications, diagnostics)
    1. Review medication dosages to date
  5. Diet Diary (7 day history of foods and symptoms)
    1. Dietary association may suggest food intolerance or Food Allergy
  6. Family History
    1. Constipation
    2. Hirschsprung's Disease
    3. Celiac Disease
    4. Cystic Fibrosis
    5. Thyroid disease
    6. Parathyroid disease
    7. Colon Cancer or Colonic Polyps
  7. Past medical and developmental history
  8. Psychosocial history (emotional stressors)
    1. May have triggered behavior change including stool witholding
    2. Autism
    3. Attention Deficit Hyperactivity Disorder

VIII. History: Reassuring suggestive of functional cause

  1. Infrequent, hard, large-caliber stools
  2. Encopresis recurs after completing Toilet Training
  3. Pain on passing stool
  4. Perianal fissures (may causes blood on stool surface)
  5. Benign abdominal exam
  6. Stool witholding behaviors
    1. Child stiffens body to contract buttocks or anal sphincter
    2. Child hides in corner while stooling in diaper, crosses legs, rocks back and forth or fidgets with each urge to defecate
    3. Results in fecal stasis with hardening and enlarging of distal stool, that becomes more difficult to pass
    4. Ultimately stretches Rectum, decreases Defecation urge Sensation and results in Stool Incontinence

IX. History: Red flag symptoms suggestive of organic cause

  1. See Hirschprung's Disease
  2. See Spinal Dysraphism
  3. No meconium by 48 hours old
    1. Hirschprung's Disease
    2. Cystic Fibrosis
    3. Congenital malformation of anorectum
    4. Spinal Dysraphism
  4. Failure to Thrive (or weight loss, Anorexia)
    1. Hirschprung's Disease
    2. Malabsorption
    3. Cystic Fibrosis
    4. Metabolic disorder
  5. Abdominal Distention
    1. Hirschprung's Disease
    2. Fecal Impaction
    3. Pseudoobstruction or other neuroenteric condition
  6. Occult blood in stool or bloody Diarrhea
    1. See History above
    2. Hirschprung's Disease
    3. Food Allergy (Cow's Milk Allergy)
  7. Abnormal Neurologic Findings (e.g. loss of Anal Wink, Cremasteric Reflex, decreased leg reflexes, strength or tone)
    1. Spinal Dysraphism
    2. Hirschprung's Disease
    3. Anorectal Malformation
  8. Constipation before 1 month of age
    1. Hirschprung's Disease
    2. Cystic Fibrosis
    3. Spinal Dysraphism
    4. Metabolic Disorders
  9. Other red flag findings
    1. Small-caliber stools
    2. Fever
    3. Abdominal Pain
    4. Nausea or Vomiting (especially Bilious Emesis)

X. Exam

  1. Growth evaluation for Growth Delay
    1. Malabsorption (Cystic Fibrosis, Celiac Disease)
    2. Hypothyroidism
  2. Abdominal exam
    1. Abdominal Distention (e.g. obstruction, Hirschprung Disease)
    2. Abdominal mass (Suprapubic fecal mass may be felt)
    3. Hepatomegaly or Splenomegaly
    4. Lax abdominal musculature (Prune Belly Syndrome)
  3. Anal inspection
    1. Anterior anus
    2. Hemorrhoids
    3. Anal Fissures
  4. Rectal Examination
    1. Optional (consider in age <1 year, red flags for organic cause, confirm disimpaction)
    2. Assessment of anal sphincter
    3. Retained stool
    4. Fecal Occult Blood Testing
    5. Evaluate for anorectal malformation
    6. Evaluate for Hirschprung Disease
  5. Back Inspection
    1. See Cutaneous Signs of Dysraphism
    2. Sacral sinuses or sacral hair tufts
  6. Neurologic Exam
    1. Lower extremity reflexes (e.g. Patellar Reflex)
    2. Lower Motor Exam and tone
    3. Anal Wink
    4. Cremasteric Reflex
  7. Miscellaneous Exam
    1. Thyromegaly or thryoid Nodules (Congenital Hypothyroidism)

XI. Diagnosis: Rome 4 Criteria for Functional Constipation <4 years old (at least 2 criteria present for 1 month)

  1. Two or less Bowel Movements per week
  2. One or more Stool Incontinence episodes per week (after Toilet Training is complete)
  3. Excessive stool retention history
  4. Painful or hard Bowel Movement history
  5. Large rectal fecal mass
  6. Large diameter stools (may plug the toilet)

XII. Diagnosis: Rome 4 Criteria for Functional Constipation >4 years old (at least 2 criteria present weekly for 1 month)

  1. Insufficient criteria for Irritable Bowel Syndrome
  2. Two or less Bowel Movements per week
  3. One or more Stool Incontinence episodes per week (after Toilet Training is complete)
  4. Excessive voluntary stool retention history (or retentive posturing)
  5. Painful or hard Bowel Movement history
  6. Large rectal fecal mass
  7. Large diameter stools (may plug the toilet)

XIV. Labs (consider if suggested by history or red flag findings)

  1. Thyroid Function Test
  2. Blood Urea Nitrogen
  3. Serum Electrolytes
  4. Serum Calcium
  5. Serum Magnesium
  6. Blood lead level
  7. Celiac panel (e.g. Tissue Transglutaminase)
  8. Sweat Test
  9. Urinalysis
    1. Constipation may increase risk of urinary infection by promoting urinary stasis

XV. Imaging (indicated for red flags above)

  1. Abdominal XRay (KUB)
    1. No benefit in Constipation (diagnosis is clinical)
      1. Berger (2012) J Pediatr 161(1):44-50 +PMID:22341242 [PubMed]
    2. Associated with increased risk of missing serious diagnosis (Intussusception, Appendicitis)
      1. Freedman (2014) J Pediatr 164(1): 83-8 +PMID:24128647 [PubMed]
  2. Unprepped Barium Enema Indications
    1. Suspected anatomic abnormalities
    2. Hirschsprung's Disease
    3. Colonic strictures from Necrotizing Enterocolitis
  3. Rectal manometry
    1. Hirschsprung's Disease
    2. Anismus
      1. Paradoxical external anal sphincter contraction
  4. Rectal suction biopsy by surgery
    1. Assess for Hirschsprung's Disease
  5. Transit study
    1. Administer radiopaque marker rings over 3 days
    2. Perform Abdominal XRAy (KUB) on third day
  6. Consider Spinal Dysraphism evaluation (L-Spine MRI)

XVI. Evaluation

  1. Initial evaluation in all patients
    1. Careful history and examination as above
    2. Consider Constipation in Children causes
  2. Red flag symptoms or signs present
    1. Pediatric Gastroenterology referral
    2. Diagnostic testing as directed by history
  3. No red flag symptoms or signs
    1. Empiric management for functional causes (see below)
    2. If no improvement with empiric therapy
      1. Consider Lab testing above
      2. Consider pediatric gastroenterology
      3. Consider pediatric psychology if no improvement in Functional Constipation after 3 months

XVIII. Prognosis

  1. Recovery from Functional Constipation in 50 to 60% of children after one year of intensive management
  2. Up to 25% will have longstanding Constipation into adulthood
  3. Bongers (2010) Pediatrics 126(1): e156-62 [PubMed]

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