The postoperative results of 50 patients who underwent straight ileoanal anastomosis after total colectomy and mucosal proctectomy were compared with those of 74 patients who underwent ileal pouch--anal anastomosis. No deaths occurred. Of the straight ileoanal anastomoses, 32% failed because of sepsis or diarrhea and necessitated abdominal ileostomy; only 1.3% failed in the pouch-anal group (P less than .05). Stool frequency among patients followed up for three months or more (straight ileoanal, n = 30; pouch-anal, n = 33) was less in the pouch-anal group (mean +/- SEM, 7 +/- 1 stools per 24 hours) than in the straight ileoanal group (11 +/- 1/24 hr, P less than .01). Major nocturnal incontinence was also less in the pouch-anal group than in the straight ileoanal group (0% v 20%), and patient satisfaction was better, as measured on a scale of 1 (very poor functional result) to 10 (excellent result) (pouch-anal score, 9; straight ileoanal score, 6; P less than .02). We concluded that ileal pouch-anal anastomosis resulted in less diarrhea, better continence, and an improved quality of life when compared with straight ileoanal anastomosis.