Obstetric fecal incontinence. Role of pelvic floor denervation and results of delayed sphincter repair.

During the last five years, 37 patients with fecal incontinence because of childbirth have been investigated. Ages varied from 22 to 62 years and duration of symptoms from 0.3 to 26 years. Anal manometry was performed in all patients and electromyography was performed in 24 patients. Thirty patients underwent delayed sphincter repair. In all patients, a dehiscence was found anteriorly, bridged by scar tissue. Continence was restored in 25 patients (83 percent). Electromyography was performed postoperatively in patients who remained incontinent and who demonstrated severe denervation. All these patients had undergone previous sphincter repair. In seven patients, there were no signs of obstetric injury. Electromyography demonstrated severe denervation, but sphincter mapping did not demonstrate muscle discontinuity. Continence improved in four patients within one year as a result of reinnervation demonstrated by electromyography. The authors conclude that fecal incontinence after childbirth may be due to either obstetric rupture or denervation. Both disorders may coexist. Delayed sphincter repair gives excellent results provided that denervation is not present. Preoperative assessment with electromyography is mandatory.