P0303Perianal fistulising Crohn’s disease in Latin America suggests variations in phenotype and clinical characteristics: A multicentre cohort study

Abstract Background Epidemiological and phenotypic variability across regions for IBD is well recognised; however, data from Latin America (LATAM) remain limited. Furthermore, specific data Crohn’s Disease (CD) related perianal fistula (PF-CD), a severe phenotype of CD is not available from across LATAM countries. This study aimed to compare the demographic, clinical, and phenotypic characteristics of PF-CD across four LATAM cohorts. Methods A retrospective study was conducted including patients with an established diagnosis of PF-CD from Argentina (N = 75), Chile (N = 49), Colombia (N = 145), and Peru (N = 22). Variables assessed included age at fistula diagnosis, CD duration prior to fistula onset, and prior exposure to immunomodulators and corticosteroids. Inter-country comparisons were performed using the chi-square test for categorical variables and the Kruskal–Wallis test for continuous variables. Results Based on the demographic profile described in Table 1, the cohort included 291 patients with a median age of 30 years at Crohn’s disease diagnosis and 31 years at PF-CD diagnosis, with a predominance of non-stricturing, non-penetrating disease (55%) and colonic or ileocolonic involvement (79%). As shown in Table 2, the median delay from CD diagnosis to PF-CD onset was 21 months 6–48, with substantial variation across countries. Overall, 54% of fistulas were classified as simple and 46% as complex. Active proctitis was present in 44% of patients, with the highest proportions observed in Argentina and Peru. Proctectomy was required in 3% of the cohort, though with notable inter-country variation. These findings highlight the clinical heterogeneity of PF-CD across Latin American settings. Conclusion This multicentre LATAM analysis demonstrates substantial inter-country variability in PF-CD presentation, including differences in disease behaviour, fistula complexity, and time to fistula development. Nearly half of patients presented with complex fistulas, and active proctitis was frequent across cohorts. These results underscore the importance of improving early detection and optimising multidisciplinary management. Overall, the findings highlight the phenotypic heterogeneity of PF-CD in Latin America and support the need for region-specific clinical strategies. Conflict of interest: Dr. Pavez, Carolina: No conflict of interest Juliao Baños, Fabián: No conflict of interest Balderramo, Domingo Cesar: No conflict of interest Cedron Cheng, Hugo Guillermo: No conflict of interest Hernandez-Rocha, Cristian: No conflict of interest Parra Izquierdo, Leidy Viviana: None Osorio, Laura: No conflict of interest Gil Parada, Fabio Leonel: No conflict of interest Puentes-Manosalva, Fabian: No conflict of interest Pizarro, Paula A.: No conflict of interest Etchevers, Maria Josefina: No conflict of interest Sobrero, Maria Josefina: No conflict of interest Montero, Joaquin: No conflict of interest Gil, Anibal Hector: No conflict of interest Sanchez, Maria Belen: No conflict of interest Sambuelli, Alicia: no Balaban, Ezequiel: No conflict of interest Rohwain, María José: No conflict of interest Alvarez-lobos, Manuel: No Conflicts Bellolio, Felipe: No conflict of interest Sepúlveda, Ignacia: No conflict of interest Hernandez, Elisa: No conflict of interest Pérez, Tamara: No conflict of interest Estay, Camila: No conflict of interest Rojas, René: No conflict of interest Sepulveda, Rolando: No conflict of interest Perez Alfaro, Ignacio: No conflict of interest Paredes Mendez, Juan: No conflict of interest Cervera Caballero, Luis: No conflict of interest Sebastian, Shaji: No conflict of interest Catalàn-Serra, Ignacio: No conflict of interest