Faecal incontinence due to external anal sphincter division in childbirth is associated with damage to the innervation of the pelvic floor musculature: a double pathology.

The commonest cause of external anal sphincter division is injury during childbirth. We have studied 20 patients with anterior external anal sphincter division using physical and electrophysiological techniques. There was evidence of pudendal nerve damage in 60% of these patients. This finding suggests that damage to the innervation of the external anal sphincter often co-exists with direct injury to the muscle; in these patients pelvic floor surgery may be required, in addition to sphincter repair itself.