Injured external anal sphincter in erectile dysfunction.

The purpose of this study was to investigate the function of the bulbocavernosus muscle in patients with faecal incontinence as a result of injury to the external anal sphincter, and to find out whether faecal incontinence had any role in erectile dysfunction. The study comprised 16 men (age 41.6+/-6.8 years) whose erectile dysfunction and faecal incontinence followed an operation for anal fistula. Erection could not be maintained until ejaculation, which, if it did occur, was not in jets. Ten healthy volunteers acted as controls. The activity of the external anal sphincter and the bulbocavernosus muscle was recorded by electromyography; anal and penile bulb pressures were also recorded. Investigations showed that erectile function was normal. The external anal sphincter was repaired, and faecal control and erectile dysfunction were assessed. Patients were followed up for 19.6+/-3.2 months. The results showed that the bulbocavernosus reflex elicited no response in either the sphincter or the bulbocavernosus muscle. Their activity, recorded by electromyography, as well as anal and bulbar pressures at rest and on voluntary squeeze, and electrostimulation of the external anal sphincter, showed a significant reduction compared to the controls. Sphincteroplasty made the patients continent and restored erectile function and ejaculation to normal. We conclude from the current study that the reduced activity of the bulbocavernosus muscle is probably caused by injury to the external anal sphincter. It is suggested that erectile dysfunction is caused by the failure, during erection, of the contraction of the bulbocavernosus muscle to raise cavernosal pressure above systolic blood pressure. The loss of the rhythmical contractions of the bulbocavernosus muscle is probably why ejaculation did not occur in jets. Repair of the external anal sphincter provided a cure for faecal incontinence and erectile dysfunction. Anorectal disorders are believed to affect erectile function, a relationship that needs further investigation.