Researchers sought to look at ileoanal pouch outcomes 20 and 30 years after surgery for a study. The research was carried out at a tertiary care referral center. Between 1980 and 1994, patients who underwent restorative proctocolectomy were identified. Those who had at least more than or equal to 20 years of in-person follow-up were included. The pouch function, pouchitis, anal stricture, and pouch failure rates were investigated. A total of 203 patients were followed for more than or equal to 20 years. About ≥30 years of follow-up was available for 71 of those. Ulcerative colitis (83%), indeterminate colitis (9%), familial adenomatous polyposis (4%), and Crohn’s disease were the most common initial diagnoses (3%). In 21% of people with ulcerative or indeterminate colitis developed Crohn’s disease later in life. The average daily stool frequency was 7 (IQR 6-8), with 38% experiencing seepage, 31% experiencing anal stenosis, 47% experiencing pouchitis, and 18% experiencing pouch failure. Over time, stool frequency increased in 41% of patients, remained constant in 43%, and decreased in 16%. Patients over the age of 50 had more daily bowel movements (median 8 vs. 6; P=0.02) and seepage (77% vs. 35%; P=0.005) than those under 50. When compared to non-patients, Crohn’s patients had higher stool frequency (median 8 vs. 6; P<0.001) and higher rates of anal stenosis (44% vs. 26%; P=0.02), pouchitis (70% vs. 40%; P<0.001), and pouch failure (38% vs. 12%; P<0.001). Patients with more than or equal to 30 years of follow-up functioned similarly to those with 20–30 years of follow-up. This was a single-institution, retrospective study. Only 35% of pouches created during the study period had more than equal to 20 years of follow-up. After 20 years, most patients retain their pouches and function reasonably well. Stool frequency and seepage increase over time. Worse outcomes were associated with advanced age and Crohn’s disease.