This study was undertaken to postoperatively assess the progression of anal sphincter function and clinical outcome in patients > or = 50 years old (Group I) compared with those < 50 years old (Group II). Clinical data were assessed after ileostomy closure by a questionnaire. These data were compiled to obtain an incontinence score, which ranged from 0 (perfect continence) to 20 (total incontinence). Anorectal manometry was performed preoperatively (MN1) and postoperatively, before (MN2) and after (MN3) ileostomy closure. Wilcoxon and paired t-test were used to compare the clinical and functional results, respectively. Group I consisted of 22 patients (mean age, 56 years) and Group II, 50 patients (mean age, 32 years). No differences were found relative to either preoperative pressures or clinical outcome. However, both the mean and high resting pressures were significantly lower in Group I at the MN2 examination. The effect on anal sphincters of ileoanal reservoir in patients over the age of 50 years is similar to that noted in younger patients. Transient impairment of internal anal sphincter function observed after ileoanal reservoir is more severe in older patients (P = 0.01). However, as in younger patients, it does completely recover after ileostomy closure.