Three-Decade Analysis of Inflammatory Bowel Disease in Türkiye: A Multicenter Study (1993-2024).

Background/Aims: Inflammatory bowel diseases (IBDs) are increasingly prevalent and challenging globally. Data regarding IBD frequency and severity between Europe and Asia are needed. The aim was to investigate the trend of IBD in Türkiye during the last 3 decades. Materials and Methods: The study was conducted retrospectively at 14 centers in Türkiye between June 1993 and March 2024. Results: Over 30 years, 4308 patients, of whom 2507 (58.2%) had ulcerative colitis (UC) and 1717 (39.9%) had Crohn's Disease (CD), were included in the study. The overall median age at the onset of IBD was 34.43 (25.28-45.64) years; the age at onset of IBD was younger in CD compared to UC (32.72 vs. 35.52 years respectively, P < .001). The peak age onset range was 28-32 years in CD, whereas 23-27 years in UC. Overall, 2526 (58.6%) patients were male. The most common location was left-sided colitis in UC patients (45.1%), followed by extensive colitis (31.2%), and proctitis (23.7%), while ileal involvement in CD patients (45.2%), afterward ileocolonic (409%), and colonic (13.5%). Both illnesses are becoming increasingly prevalent. The UC/CD ratio tends to decrease over time. During the study period, 1577 (36.6%) patients received biologic treatment. During the study period, 418 (24.3%) underwent resective surgery for CD and 88 (3.5%) total colectomy for UC; the major abdominal surgery has declined over time. Conclusion: The frequency and characteristic features of IBD in Türkiye appear to be between Europe and Asia. Over time, while the usage of biologic therapy and the rate of CD have increased, the frequency of surgery has decreased.