One hundred nine men and 71 women with a mean age of 31 years had construction of 164 S, 2 J, and 14 other ileoanal reservoirs. Postoperative gastrointestinal complications included small bowel obstruction in 11 percent and ileus, hemorrhage, and sepsis in 6 percent, 5 percent, and 11 percent, respectively. There was a 13 percent incidence of miscellaneous postoperative complications. Pouch perianal fistulas developed in 5 percent of patients, and pouch vaginal and other pouch fistulas developed in an additional 4 percent. During long-term follow-up small bowel obstruction developed in 27 percent of patients, and enterolysis or enterectomy was required in 15 percent of patients. One hundred fourteen patients who were followed for a mean length of 5 years after ileostomy closure (range 16 to 88 months) were evaluated for functional outcome. Function improved with time in 63 percent of patients and remained stable in another 33 percent; only 4 percent had long-term deterioration. Ninety-five percent of patients would again choose an ileoanal reservoir over a permanent ileostomy. This long-term assessment shows that although the ileoanal reservoir is a viable option in the management of mucosal ulcerative colitis, it should not be recommended to every patient.