P0430Crohn’s Disease of the Pouch: Presentation, Management and Outcomes in a Canadian Tertiary Centre

Abstract Background Crohn’s Disease of the Pouch (CDP) is a rare and clinically challenging phenotype of ileal pouch–anal anastomosis (IPAA) in patients initially diagnosed with ulcerative colitis. Limited understanding of the mechanisms underlying CDP prevent standardized guidance for diagnostic criteria and subsequent treatment approaches. We aimed to evaluate patients with documented CDP to identify pre-, intra-, and postoperative characteristics associated with disease control. Preoperative disease characteristics, intraoperative findings, and postoperative pharmacological therapy decisions were assessed in correlation to clinically active disease. Methods A retrospective chart review was conducted on 27 patients diagnosed with CDP between 2005 and 2025 at London Health Sciences Center and St. Joseph’s Healthcare in London, Ontario. Demographic, preoperative, intraoperative, endoscopic, histologic, and pharmacologic data were collected. The primary outcome was clinical disease control status, defined as symptomatic remission with or without endoscopic remission. The data are presented as mean with standard deviation (SD) for normally distributed continuous variables. Categorical data are presented by absolute and relative frequencies (n and %). To account for associations between outcomes and covariates, we used chi square test. Results Mean age was 51.5 ± 10.7 years, 53.8% male, 88.9% had preoperative pancolitis and underwent a staged IPAA. Clinical disease control was achieved in 69% and was associated with fewer surgical interventions (p = 0.026), and fewer imaging abnormalities (p = 0.009). Pouch retention remained similar across patients who achieved disease control and those who did not (p = 0.419). Across patients with well controlled CDP, biologic therapy varied by remission status: those with clinical and endoscopic remission were most often treated with anti–IL-12/23 agents (5/7, 71.4%), while patients with clinical but not endoscopic control were largely maintained on anti-TNF therapy (5/11, 45.5%). Other maintenance regimens included anti–IL-23 therapy (4/11, 36.4%), additional anti-TNF use (1/11, 9.1%), and combination 5-ASA with antibiotic therapy (1/11, 9.1%). Conclusion While diagnosing CDP remains a clinical challenge, our findings demonstrate the need for routine cross-sectional imaging in assessment and monitoring, as well as phenotype-based treatment selection of biologic therapy. Although limited by sample size and retrospective design, this study’s integration of imaging, endoscopy, histology, and longitudinal outcomes provides a real-world framework to guide multimodal management and preserve pouch function. References: 1. Barnes EL, Kochar B, Jessup HR, Herfarth HH. The incidence and definition of Crohn’s disease of the pouch: a systematic review and meta-analysis. Inflamm Bowel Dis. 2019;25(9):1474-1480. doi:10.1093/ibd/izz005 2. Mark-Christensen A, Erichsen R, Brandsborg S, Pachler FR, Nørager CB, Johansen N, et al. Pouch failures following ileal pouch-anal anastomosis for ulcerative colitis. Colorectal Dis. 2018;20(1):44-52. doi:10.1111/codi.13802 3. Alsafi Z, Snell A, Segal JP. Prevalence of “pouch failure” of the ileoanal pouch in ulcerative colitis: a systematic review and meta-analysis. Int J Colorectal Dis. 2022;37(2):357-364. doi:10.1007/s00384-021-04067-6 4. Fadel MG, Geropoulos G, Warren OJ, Mills SC, Tekkis PP, Celentano V, Kontovounisios C. Risk factors associated with the development of Crohn’s disease after ileal pouch-anal anastomosis for ulcerative colitis: a systematic review and meta-analysis. J Crohns Colitis. 2023;17(9):1537-1548. doi:10.1093/ecco-jcc/jjad051 Conflict of interest: Ms. Wadhwani, Arpana: No conflict of interest Alobaid, Saleh: No conflict of interest Mortuza, Rokhsana: No conflict of interest Townsend, Cassandra: No conflict of interest Ponich, Terry: No conflict of interest Khanna, Reena: No conflict of interest Jairath, Vipul: Consulting Fees: Abbvie, Alimentiv, Amgen, Anaptys Bio, Asahi Kasei, Asieris, Astra Zeneca, Attovia, Blackbird Labs, BMS, Boehringer Ingleheim, Biomebank, Caldera, Calluna, Catalytic Health, Celltrion, Ensho, Enthera, Exeliome Biosciences, Ferring, Fresenius Kabi, Gilead, Granite Bio, GSK, Janssen, Lilly, Merck, Mountainfield, MRM Health, Nxera, Organon, OSE Immunotherapeutics, Pendopharm, Pioneering Medicine, Pfizer, Prometheus, Roche/Genentech, Sanofi, SCOPE, Shattuck Labs, Sorriso, Spyre, Synedgen, Takeda, Teva, Tillotts, Union Therapeutics, Ventus, Ventyx, Vividion, Xencor, Zealand Pharma. Sedano, Rocio: consulting/advisory board fees from AbbVie, Alimentiv, Pendopharm and Takeda.