Total proctocolectomy with creation of an ileoanal reservoir (IAR) is currently the preferred surgical treatment of mucosal ulcerative colitis and familial adenomatous polyposis. However, the creation of an IAR on older patients is controversial and commonly avoided because of anticipated poor functional results and increased morbidity. We prospectively studied 140 consecutive patients who underwent a double stapled IAR (DSIAR) between 1988 and 1993. We compared the outcome of 14 patients (Group I) 60 years of age or older (mean 65, range 60-71 years; 10 males and 14 females), to 126 patients (Group II) under the age of 60 (mean 37, range 12-59 years; 80 males and 14 females). Mucosal ulcerative colitis and indeterminate colitis were noted, respectively, in 12 (93%) and 1 (7%) patients in Group I and in 94 (75%) and 5 (4%) patients in Group II. In Group II, 21 (16%) patients had familial adenomatous polyposis, and 6 (5%) had a postoperative diagnosis of Crohn's disease. Subjective functional results and anal manometry were assessed in all 14 patients in Group I (100%) and in 110 of the 117 patients in Group II (94%) whose stomas were closed at a mean followup of 24 (3-60) months. Manometry was per- formed before, and 2 and 12 months after surgery. Patients in Groups I and II reported a mean of 6.2 and 5.2 bowel movements during the day (P=NS), and 2 and 1.1 at night, respectively (P<0.05). A total of 12 (86%) patients in Group I and 104 (95%) in Group II reported perfect or almost perfect continence at night (P=NS), and 12 (93%) patients in Group I and 104 (95%) in Group II reported perfect or almost perfect continence during the day (P=NS). The preoperative mean and maximal resting pressures were similar in both groups (71.7 mmHg and 94 mmHG in Group I and 71.6 and 88 mmHg in Group II respectively; P=NS). Postoperative resting pressure changes were also similar in both groups P=NS), with a similar significant decline 2 months after surgery, which recovered by 12 months after surgery in both groups. There were no significant changes between the pre- and postoperative mean and maximal squeeze pressures in either group. The overall morbidity and mortality rates in Groups I and II were 21 and 0 per cent, and 21 and 0.8 per cent, respectively (P=NS). DSIAR in patients 60 years of age or older is as safe and is associated with as good functional and physiologic results as it is in younger patients. Thus, this procedure may be offered to older patients with expectation of good outcome.