Recovery of anal sphincter function following transabdominal repair of rectal prolapse: cause of improved continence?

Twenty-eight patients with complete rectal prolapse underwent anorectal manometry before and 6 months and 1-2 years after abdominal rectopexy and sigmoid resection in a study of the mechanisms responsible for postoperatively improved anal continence. Preoperatively, 22 patients reported defective and control. Seven patients (all with minor incontinence) regained normal control and eight other patients achieved improved continence after surgery. Anal resting, squeeze, and voluntary contraction pressures were significantly lower for defective than for normal control, with a significant rise in these pressures at 6 months after the operation, except for those incontinent patients in whom continence was not improved. No further pressure rise was seen later. Improvement of continence was not accompanied by changes in rectal sensation or reflexive functions of the internal anal sphincter. These results suggest that recovery of the resting and voluntary contraction functions of the sphincter muscles was the cause of continence improvement observed after surgery. Anal manometry was unable to predict outcome of function. Therefore, supplementary procedures for restoration of continence are not advisable, although patients with only minor incontinence are likely to regain full continence after rectopexy alone.