Anal sphincter function and rectal reservoir after sphincter saving operations for carcinoma of the rectum.

Anal sphincter function and rectal reservoir were studied in 27 patients after low anterior resection, in 6 after Welch or Turnbull type pull-through surgery and in 3 after Bacon type pull-through surgery. Sixteen patients who had undergone right hemicolectomy served as a control group. Anal sphincter function immediately after low anterior resection was diminished, but improved during the following 6 months. Rectal capacity was much reduced immediately after surgery, but increased with time, and the neorectum could to some extent adapt to its new role as a reservoir. After pull-through operations, anal canal pressure and rectal compliance were significantly lower than after low anterior resection or right hemicolectomy. These findings may explain the increased frequency of bowel action after pull-through operations.