BACKGROUND: This study aimed to report the experience over 40 years and outcomes of 5070 patients who underwent a pelvic pouch procedure. METHODS: A retrospective analysis of a prospectively maintained ileal pouch-anal anastomosis (IPAA) database (1983-2022) was performed. Patients were stratified based on the following diagnoses: ulcerative colitis (UC), indeterminate colitis (IC), familial adenomatous polyposis (FAP), inflammatory bowel disease (IBD)-dysplasia, Crohn colitis (CD), and others. The long-term IPAA outcomes, quality of life, and satisfaction with IPAA over time were studied. RESULTS: The Kaplan-Meier pouch survival rates at 20 years based on the diagnosis were as follows: 92% (95% CI, 90%-94%) for UC, 87% (95% CI, 81%-94%) for CD, 95% (95% CI, 92%-99%) for FAP, and 92% (95% CI, 89%-96%) for IC. Of the patients with UC, 28% developed pouchitis, 12% developed anastomotic stricture, and 13% developed small bowel obstruction. Patients with IC had the highest rate of pouchitis (347 [37%]) and IPAA strictures (154 [17%]). Patients with CD had the highest rate of fistula (26 [15%]). Patients with FAP had the highest rate of obstruction (41 [25%]). The social lifestyle restrictions were predominant among patients with FAP (20%) compared with those with UC (12%) or CD (13%) (P =.004). The median stool frequency was 6 (IQR, 5-8) among the groups (P =.46). CONCLUSION: Patients with an IBD diagnosis and IPAA were at an increased risk of pouch-associated complications, such as pouchitis, strictures, and pelvic sepsis. Patients with FAP had the best pouch survival with significantly lower rates of pouch-associated complications.