Peak incidence: Transitions in child’s life (infancy with solid food introduction, toilet training at 2-3 yrs, and school entry). c
Withholding behavior: Painful bowel movement (BM) leads to fear of defecation, initiating a vicious cycle of voluntary stool retention.
Low-fiber diet and excessive cow’s milk intake (>24 oz/day).
Emotional stressors (e.g., starting school, new sibling, lack of toilet privacy).
Clinical Features
History:
<2 defecations per week.
History of stool withholding (e.g., stretching, arching, hiding, rocking during urges).
Large-diameter, hard stools that may clog the toilet.
Intermittent abdominal pain, bloating, and early satiety.
Encopresis (fecal incontinence due to leakage of liquid stool around a hard impaction; often mistaken for diarrhea).
Physical Exam:
Palpable, firm abdominal mass in the left lower quadrant (LLQ) or suprapubic area.
Anal fissures or skin tags from chronic hard stools. c
Digital Rectal Exam (DRE): Rectum filled with large, hard stool, normal sphincter tone (avoid routine DRE unless diagnosis is unclear).
Normal spine/gluteal cleft (no dimples, tufts of hair, or sacral abnormalities).
Diagnosis
Initial/Screening: Clinical Dx based on Rome IV criteria (requires ≥2 criteria for at least 1 month: ≤2 BMs/wk, history of withholding, painful/hard BMs, large fecal mass, fecal incontinence).
Confirmatory/Gold Standard: Clinical Dx based on history and physical exam; no routine labs or imaging required.
Key Labs:
Generally not indicated unless organic red flags are present (e.g., poor growth, delayed development).
If organic cause suspected: TSH/free T4 (hypothyroidism), tTG IgA (celiac disease), serum calcium.
Imaging:
Abdominal X-ray: Shows fecal loading in the rectosigmoid. Not routinely recommended; reserved for obese pts or when physical exam is impossible/uncooperative.
Biopsy:
Rectal suction biopsy: Gold standard if Hirschsprung disease (HD) is suspected; demonstrates the absence of ganglion cells and hypertrophied nerve fibers.
Differential Diagnostics
Hirschsprung Disease:
Diff by delayed meconium passage (>48 hrs of life), failure to thrive (FTT), explosive release of stool/gas upon DRE (squirt sign), and an empty rectal vault.
Infant Dyschezia
Infants < 9 months of age; Soft, normal, or loose stools; Reassurance only; avoid laxatives and rectal stimulation
Celiac Disease:
Diff by poor growth/FTT, chronic diarrhea alternating with constipation, abdominal distension, and (+) tTG IgA.
Hypothyroidism:
Diff by hypotonia, lethargy, poor linear growth, umbilical hernia, macroglossia, and ↑ TSH / ↓ free T4.
Spina Bifida Occulta / Spinal Cord Pathology:
Diff by lumbosacral abnormalities (tuft of hair, dimple, birthmark), abnormal lower extremity reflexes, and decreased anal sphincter tone.
Cystic Fibrosis:
Diff by history of meconium ileus at birth, recurrent respiratory infections, pancreatic insufficiency, and (+) sweat chloride test.
Management
Disimpaction (if fecal mass/impaction present):
First-line: High-dose oral polyethylene glycol (PEG) (osmotic laxative) titrated to effect. c
Second-line: Enemas (saline or mineral oil) if oral route is refused or unsuccessful.
Maintenance Therapy (First-line):
Daily PEG (maintenance dose) for at least 3-6 months. Do not stop laxatives early; bowel must shrink to normal size.
Dietary modifications: ↑ fiber, ↑ water intake, and limiting cow’s milk to <16-24 oz/day.
Behavioral training: Timed toilet sits for 5-10 mins post-meals (utilizing gastrocolic reflex) with positive reinforcement (e.g., reward charts).
Refractory Cases (Second-line / Referral):
Add stimulant laxatives (e.g., senna, bisacodyl) for short-term rescue use.
Refer to pediatric GI for further workup (e.g., anorectal manometry to rule out HD or dyssynergic defecation).
Complications
Anal fissures: Painful defecation that perpetuates the withholding cycle.
Encopresis: Overflow fecal incontinence causing significant social and psychological distress.
Recurrent UTIs or urinary incontinence: Large rectosigmoid fecal mass compresses the bladder, causing urinary stasis.