Abnormalities of innervation of internal anal sphincter in fecal incontinence

Abstract

Physiological and histological studies have shown that the internal anal sphincter is abnormal in idiopathic fecal incontinence. We have recently demonstrated that the in vitro contractile response of the internal anal sphincter to the sympathetic neurotransmitter noradrenaline is decreased in incontinence. In this study we have further defined this reduced sensitivity and provided more information about the intrinsic innervation in both the normal and the incontinent sphincter muscle. Muscle strips from 12 incontinent patients undergoing post anal repair and from 11 controls undergoing rectal excision for low rectal carcinoma were studied. Responses to noradrenaline were recorded initially ..