P1253 Montréal Classification Phenotypes in Moroccan Inflammatory Bowel Disease: Distribution and Comparison with International Series

Abstract

Abstract Background The Montréal classification is a key framework for describing phenotypic variation in inflammatory bowel disease (IBD) and guiding treatment decisions. Data from North Africa remain scarce, and comparisons with international cohorts can highlight specific epidemiologic patterns. Methods We analyzed phenotypic distribution according to the Montréal classification in a cross-sectional Moroccan IBD cohort (2016–2023) including 415 Crohn’s disease (CD) patients and 231 ulcerative colitis (UC) patients. For CD, age at diagnosis (A), disease behavior (B), and location (L) were assessed; for UC, disease extent (E) was recorded. Results were compared descriptively with those reported in large European, Asian, and Middle Eastern series. Results Crohn’s disease (n = 415) • Age at diagnosis (A): A1 (<17 y) 10.5%; A2 (17–40 y) 69.9%; A3 (>40 y) 18.8% • Behavior (B): B1 (non-stricturing, non-penetrating) 35.4%; B2 (stricturing) 35.9%; B3 (penetrating) 28.0% • Location (L): L1 (ileal) 29.5%; L2 (colonic) 18.7%; L3 (ileocolonic) 48.2%; other ≤2% Ulcerative colitis (n = 231) • Extent (E): E1 (proctitis) 12.5%; E2 (left-sided) 37.5%; E3 (extensive/pancolitis) 49.1% Comparisons with literature • The predominance of A2 in CD mirrors findings from European and Middle Eastern series, although the proportion of A1 in Morocco (10.5%) is slightly higher than reported in many Western cohorts (∼5–8%). • B2/B3 behaviors collectively exceed 60% in Morocco, a higher rate of complicated disease than in many Western series (∼40–50%), and closer to rates reported in certain Middle Eastern and South Asian populations. • L3 (ileocolonic) is the dominant location (48.2%) in Morocco, similar to other North African and Asian series, but higher than in many European cohorts (∼30–40%). • In UC, the high proportion of E3 extensive colitis (∼50%) exceeds that reported in Western Europe (∼20–30%), aligning more closely with findings from Middle Eastern and some Asian cohorts. Conclusion In this Moroccan IBD cohort, CD is characterized by early adult onset (A2), a high burden of complicated behaviors (B2/B3), and predominance of ileocolonic location (L3). UC shows an unusually high frequency of extensive colitis (E3). These patterns more closely resemble Middle Eastern and certain Asian populations than Western European cohorts, suggesting possible environmental or genetic influences. Conflict of interest: Naciri, Fatine: No conflict of interest Elmqaddem, Ouiam: No conflict of interest Koulali, Hajar: No conflict of interest Zazour, Abdelkrim: No conflict of interest Ismaili, Zahi: No conflict of interest Kharrasse, Ghizlane: No conflict of interest