Improvement in Functional Outcomes Following Ileal Pouch-Anal Anastomosis: Results from the United States Ileal Pouch-Anal Anastomosis Study

BACKGROUND: Ileal pouch-anal anastomosis is the standard procedure for patients with ulcerative colitis or unclassified inflammatory bowel disease seeking intestinal continuity post-proctocolectomy. Previous studies on function are limited by retrospective design, single-center scope, and insufficient functional domain data. OBJECTIVE: To provide prospective, multicenter data on functional outcomes after ileal pouch-anal anastomosis. DESIGN: Prospective cohort study. SETTINGS: Several North American centers. PATIENTS: Adults scheduled for ileal pouch-anal anastomosis between June 2018 and June 2022. MAIN OUTCOME MEASURES: Patient-reported colorectal (COREFO, Wexner Fecal Incontinence), sexual (PROMIS Sex-FS), urinary (International Prostate Symptom Score), and global (PROMIS Global-10) function. RESULTS: A total of 203 patients were included (mean age, 35.8 ± 13.4, 59% male). Most had UC (95%) with refractory disease the most common surgical indication (91%). Fifty-seven patients (28%) had subtotal colectomy without ileal pouch-anal anastomosis. Bowel function improved significantly after ileal pouch-anal anastomosis (COREFO mean, 50.6 ± 18.8 at baseline to 24.3 ± 17.7 at 12 months, p < 0.0001; Wexner mean 8.2 ± 5.3 at baseline to 4.3 ± 4.5 at 12 months, p < 0.0001) as did global health satisfaction (mental health mean T-score 41.5±10.8 at baseline to 51.2 ± 10.3 at 12 months, p < 0.0001; physical health mean T-score 39.2±9.2 at baseline to 52.2 ± 9.2 at 12 months, p < 0.0001). Sexual interest increased for both females (mean T-score, 34.2 ± 13.2 at baseline to 41.9 ± 13.0 at 12 months, p = 0.007) and males (mean T-score, 39.4 ± 13.8 at baseline to 51.1 ± 9.6 at 12 months, p < 0.0001); other sexual domains were stable. Urinary function remained stable (mean, 7.2 ± 6.3 at baseline to 5.4 ± 6.3 at 12 months, p = 0.08). Surgical indication significantly associated with postoperative bowel function (p = 0.0003). LIMITATIONS: Sample size is limited; follow-up limited to 12 months. CONCLUSION: In this prospective multicenter cohort, ileal pouch-anal anastomosis led to significant improvements in bowel function, continence, sexual interest, and overall health, with no decline in urinary or other sexual functions. These findings support the role of ileal pouch-anal anastomosis in restoring function and inform preoperative counseling and decision-making.