Childhood encopresis

Specialty: Pediatrics.

• Functional fecal incontinence
• fecal leak due to overflow
• fecal soiling

Why it occurs

• Chronic functional constipation with prolonged fecal retention (rectal fecaloma that distends the walls of the colon, reducing sensitivity and allowing the passage of liquid feces due to overflow)
• Behavioral factors or defecation avoidance (pain before evacuating due to anal fissure, toilet phobia or early/coercive start of sphincter training)
• Anxiety disorders, environmental stress or opposition dynamics (family conflicts, bullying, moving or birth of a sibling)
• Neurodevelopmental disorders (ADHD, Autism Spectrum Disorder with difficulties in proprioception and sensory desensitization)
• Underlying anatomical or neurological abnormalities (occult spina bifida, mild anal stenosis or visceral myopathies, rare)

Initial workup

Detailed physical examination that includes inspection of the perianal area (fissures, position of the anus, anal reflex), abdominal palpation in search of fecal masses, and neurological evaluation of the lower extremities and deep tendon reflexes. Rectal examination is reserved for diagnostic doubts by palpating the rectal blister filled with hard stools. Plain abdominal x-ray (only if palpation or digital rectal examination is inconclusive to confirm fecal load). Rectal ultrasound to measure the diameter of the rectal sheath (a diameter of the posterior wall of the bladder to the rectal wall > 3 cm supports the diagnosis of megarectum).

Standard management

• Polyethylene glycol 3350 with or without electrolytes — osmotic laxative of choice, safe in the long term; disimpaction dose of 1 to 1.5 g/kg/day orally for 3-6 days, followed by maintenance doses of 0.2 to 0.8 g/kg/day to ensure effortless soft stools
• Lactulose — osmotic alternative if PEG is not tolerated; dose of 1 to 3 ml/kg/day divided into one or two doses
• Sodium phosphate or saline enemas — reserved exclusively for rapid rectal disimpaction under supervision, limiting its use in children under 2 years of age due to the risk of severe electrolyte disorders
• Paraffin oil or liquid Vaseline (lubricant; dose of 1 to 3 ml/kg/day, contraindicated in infants or children with dysphagia due to risk of lipoid pneumonia due to aspiration).