Description

• Voluntary or involuntary fecal soilage in a (typically) previously toilet-trained individual
  • Age may be chronologic or developmental.
  • No underlying organic disease
  • At least one event per month for 3 months
  • Classified into functional constipation (retentive encopresis) and functional nonretentive fecal incontinence (FNRFI); both cause fecal incontinence. There is no constipation in FNRFI. Functional constipation is more common.
• Adult encopresis (fecal incontinence) is a separate topic.
• System(s) affected: GI; psychological
• Synonyms(s): fecal incontinence, soiling

Epidemiology

Incidence
Predominant sex: male > female (4 to 6:1). Constipation accounts for 3% of general pediatric referrals; up to 84% of constipated children have fecal incontinence at some point.

Prevalence
Occurs in 1–3% of children 4 years of age

Etiology and Pathophysiology

• In 90% of cases, encopresis develops as a consequence of chronic constipation, with resulting overflow incontinence (retentive encopresis). The other 10% are caused by specific organic etiologies.
• Chronic constipation with irregular and incomplete evacuation results in progressive rectal distension and stretching of the internal/external anal sphincters.
• Chronic rectal distension causes habituation, leading to the loss of sensing the normal urge to defecate. Eventually, soft or liquid stool leaks around the retained fecal mass.
• Many children voluntarily withhold stool in response to the urge to defecate for fear of pain or a preoccupation with not interrupting social activities.
• Psychological
  • Stool withholding, fear, anxiety
  • Difficulty with toilet training, including unusual anxiety or conflict with parent
  • Resistance to using public toilet facilities, such as school bathrooms or outdoor toilets
  • Known association with sexual abuse in boys; likely similar association in girls
  • Developmental delay
• Anatomic
  • Rectal distension and desensitization
  • Anal fissure or painful defecation
  • Muscle hypotonia
  • Slow intestinal motility
  • Hirschsprung disease
  • Cystic fibrosis
  • Spinal cord defects (e.g., spina bifida)
  • Congenital anorectal malformations
  • Anal stenosis
  • Anterior displacement of the anus
  • Postoperative stricture of anus or rectum
  • Pelvic mass
  • Neurofibromatosis
• Dietary or metabolic
  • Inadequate dietary fiber; excessive protein or milk intake; inadequate water intake
  • Hypothyroidism; hypercalcemia; hypokalemia
  • Diabetes insipidus; diabetes mellitus
  • Food allergy
  • Gluten enteropathy
• Medication side effects

Genetics
None known; although incidence may be higher in children with family history of constipation

Risk Factors

• Male gender
• Constipation
• Very low birth weight
• Painful defecation
• Difficulty with bowel training, including social pressure related to early daycare placement
• Organic/anatomic causes
• Anxiety and depression
• Insufficient fluid or fiber intake
• Refusal to use public restrooms
• Attention deficit
• History of abuse

General Prevention

Family education: toilet training when ready; optimize fluid and fiber intake.

Commonly Associated Conditions

• Constipation, Hirschsprung disease
• Cerebral palsy, cystic fibrosis
• Developmental and behavioral diagnoses, urinary incontinence