Abstract
Electrical activity of the external sphincter in fifteen patients with anorectal malformations (7 patients with the high type anomaly, 4 with the intermediate type, and 4 with the low type), aged 3 to 14, was investigated. The results were compared with those of 3 normal subjects, aged 6 to 10. The electrical activity of the external sphincter in the patients with high type anomaly was found to be disturbed from the points of tonic activity, inflation reflex, and activity during further rectal inflation. The patients with intermediate type or those with the low type, how-ever, showed good preserved electrical activity of the external sphincter as well as normal control did. The phasic activity of EMG was found in the 3 types of anorectal malformations. This result indicated that patients with the high type anomaly could gain good voluntary control of defecation by having a training of voluntary contraction.
