Recovery of the internal anal sphincter following rectopexy: a possible explanation for continence improvement.

Twenty-one patients suffering from rectal prolapse (n = 15) or internal rectal procidentia (n = 6) were investigated clinically and by anorectal manometry prior to and six months following retopexy. Rectal prolapse was associated with incontinence in 67% (10/15) of the patients preoperatively. The moderately or severely incontinent patients had lower than normal maximum anal resting pressures (MAP) and those with severe incontinence also had lower than normal maximum squeeze pressure (MSP). Postoperatively only 20% (3/15) of the patients remained incontinent and none of them suffered severe incontinence. MAP values increased significantly indicating that improvement of the function of the internal anal sphincter may be one of the factors contributing to better continence. Rectal sensibility was impaired in patients with rectal prolapse as compared to 15 controls. There was no postoperative change. Patients with internal rectal procidentia had normal MAP and MSP and no postoperative change could be demonstrated.