DEFINITION
- Voluntary or involuntary passage of feces into inappropriate places.
- Frequency: Occurs at least once a month for 3 consecutive months.
- Age Criteria: Chronological or developmental age of 4 years.
- Exclusion: Not exclusively secondary to direct effects of a substance (e.g., laxatives) or general medical condition (except constipation).
CLASSIFICATION
Categorized into two distinct subtypes requiring different management approaches.
| Feature | Retentive Encopresis | Non-Retentive Fecal Incontinence (FNRFI) |
|---|---|---|
| Frequency | 65–95% of cases. | 5–10% of cases. |
| Pathophysiology | Constipation with overflow incontinence. | Normal transit; psychosocial etiology. |
| Rectal Exam | Dilated rectal vault filled with hard stool. | Normal rectal tone; empty rectal vault. |
| Fecal Mass | Present (palpable suprapubic/rectal mass). | Absent. |
| Stool Volume | Small smears or liquid overflow. | Passage of entire rectal contents. |
PATHOPHYSIOLOGY
Retentive Encopresis
- Initiated by painful defecation (e.g., anal fissure, hard stool) leading to voluntary/subconscious stool withholding.
- Chronic retention causes progressive rectal dilatation (megarectum) and increased rectal compliance.
- Desensitization of rectal stretch receptors diminishes normal urge to defecate.
- Proximal liquid colonic contents percolate around hard, retained distal fecal impaction.
- Liquid stool leaks through relaxed anal sphincter unperceived by child (overflow incontinence).
Non-Retentive Fecal Incontinence (FNRFI)
- Colonic transit time, segmental transit, and rectal compliance remain entirely normal.
- Strongly associated with psychological comorbidities (ADHD, anxiety, depression, oppositional defiance).
- Highly linked to stressful life events (bullying, birth of sibling, maltreatment).
CLINICAL EVALUATION
History
- Underwear soiling often misinterpreted by parents as chronic diarrhea.
- Retentive posturing (gluteal clenching, leg stiffening, crossing legs, hiding in corners) often mistaken for straining.
- Associated symptoms: Abdominal pain, poor appetite, large-caliber stools obstructing toilet.
- Concomitant enuresis or recurrent urinary tract infections (UTI) due to bladder compression.
Physical Examination
- Abdomen: Palpable large, firm fecal mass in suprapubic area or left lower quadrant.
- Perineum: Fecal smears, perianal excoriation, anal fissures, or skin tags.
- Digital Rectal Exam (DRE): Dilated vault with guaiac-negative stool (Retentive); empty vault (Non-retentive).
- Neurological Screen: Mandatory assessment of anal wink, cremasteric reflexes, lower extremity tone/reflexes, and sacral inspection (dimple, hair tuft) to exclude spinal dysraphism/tethered cord.
ALARM SIGNS (RED FLAGS)
Exclude functional encopresis if present:
- Delayed meconium passage >48 hours (Hirschsprung disease).
- Ribbon-like stools or explosive discharge upon DRE withdrawal.
- Absent anal wink or deep tendon reflexes (Spinal cord anomaly).
- Blood in stool not attributable to anal fissure.
- Severe abdominal distension with bilious vomiting.
MANAGEMENT PROTOCOL
Management depends strictly on subtype. “REO” approach (Resuscitate, Evaluate, Operate) applies to acute bleeding, but functional encopresis utilizes education, disimpaction, and maintenance.
1. Education & Demystification (Both Subtypes)
- Alleviate guilt. Explain overflow soiling is involuntary and caused by loss of normal sensation.
- Eliminate retaliatory or punitive measures (scolding exacerbates withholding).
- Establish positive reinforcement (star charts/rewards for toilet sitting, not just for staying clean).
2. Disimpaction (Retentive Only)
Mandatory first step before maintenance therapy to prevent worsening of overflow soiling.
- Oral Route: High-dose Polyethylene Glycol (PEG 3350) 1–1.5 g/kg/day for 3–6 days.
- Rectal Route: Phosphate enemas or glycerin suppositories (maximum 120 mL, avoid repeated use).
- Manual: Rare; requires general anesthesia for severe, refractory impaction.
3. Maintenance Therapy (Retentive Only)
Goal: 1-2 soft, painless stools daily. Continue for minimum 2 months; taper gradually once toilet training complete and symptoms absent for 1 month.
- Osmotic Laxatives (First-line): PEG 3350 (0.3–0.8 g/kg/day) or Lactulose (1-2 g/kg/day).
- Stimulant Laxatives (Rescue/Refractory): Senna or Bisacodyl used intermittently to prevent re-impaction and facilitate rectal emptying.
- Lubricants: Mineral oil (avoid in infants <1 year or neurologically impaired due to lipid pneumonitis risk).
4. Behavioral & Dietary Modifications
- Toilet Sitting: 5–10 minutes post-prandial (utilizes gastrocolic reflex) 2-3 times daily.
- Posture: Footstool use for optimal anorectal angle; relaxation of pelvic floor.
- Diet: Normal age-appropriate fiber (Age + 5-10 grams) and adequate fluid intake. Excessive fiber may worsen gas/pain.
5. Specific Management for Non-Retentive Fecal Incontinence (FNRFI)
- Conventional laxatives and enemas are ineffective and contraindicated.
- Primary therapy requires strict, scheduled toilet training and psychological/behavioral health intervention.
- Screen for underlying learning disabilities, ADHD, or abuse.
- High success rate with maturity; 85% resolve by age 18.