1. Organic causes of faecal incontinence in children
• Repaired anorectal malformations
• Post-surgical Hirschsprung disease
• Spinal cord trauma
• Spinal cord tumours
• Cerebral palsy
• Myopathies affecting the pelvic floor muscle and external anal sphincter
2. Functional cause of faecal incontinence
Functional constipation associated with faecal incontinence- (Retentive FI)
• Rectum loaded with faeces leading to overflow incontinence due to witholding.
• Withholding leads to megarectum and mega colon and decreased propulsive contractile forces of the rectal musculature
• Rectal sensitivity is blunted due to rectal hyposensitivity or constant accumulation of faeces
• Semi liquid faeces seeps between the faecal mass and rectal wall and escape through the anal canal when sphincter muscle is relaxed
- Leaked stools are generally small
- Incontinence of faeces can occur in day or at night
• 29-34% of children with FI have daytime wetting
Functional non-retentive FI-massive poos in pants but not constipated
• Large amounts of poo without knowing it happens e.g. 1x week or 1x month- complete evacuation of the bowels, not just staining the underwear
• Regularly pass stools on toilet with no pain or difficulty
• Usually have leaks in the afternoon due to fatigue of the pelvic floor muscle.
• On anorectal manometry the inability to relax the external anal sphincter is seen- likely to be an acquired control mechanism after first involuntary passage of stool
• Child is older than 4 years
- Now evidence of faecal retention
• Defecation into place inappropriate to the social context at least once a month
• No evidence of inflammatory, metabolic, or neoplastic process to explain the symptoms
• Colonic transit time, rectal compliance and sensory thresholds are normal