Anorectal motility after surgery for spina bifida.

Anorectal motility was studied in 93 children (aged 15 days to 16 1/2 years) who had undergone surgery for myelocele or meningomyelocele, and 80 controls, matched for age and sex. Mean resting pressure in the anal canal of patients was markedly decreased, particularly in the presence of incontinence, and unstable. The recording of a rectoanal inhibitory reflex both in the upper anal canal and at the anal margin was associated with the presence of fecal incontinence and motor disorders of the lower extremities. Patients could be divided into four groups according to manometric pattern: 1) those with normal recordings (incontinence in 63 per cent), 2) those with spontaneous intermittent relaxations of the upper anal canal and simultaneous rectal contractions (incontinence in 91 per cent), 3) those with normal manometry except for unstable upper anal canal pressure (incontinence in 92 per cent), and 4) those with absence of the rectoanal inhibitory reflex and hypotonic anal canal (patients too young to appraise continence, all under 2 years).