A trend analysis of inflammatory bowel disease in non-endemic era (1993-2023)

Aims: In this study, we aimed to evaluate the demographic and epidemiological trends of ulcerative colitis (UC) and Crohn’s disease (CD) in non-endemic era for inflammatory bowel disease (IBD) during the past three decades. Methods: UC and CD patients who had follow-up at least 6 months between June 1993 and February 2023 were evaluated retrospectively. Electronic medical databases, personal queries and IBD registries have all been used to collection data on the clinical and demographic characteristic of all patients. Results: A total of 1549 adult patients with UC and CD were admitted to study. UC was diagnosed in 873 (56.4%) patients (male 538, 61.6%) and CD was diagnosed in 676 (43.6%) patients (male 404, 59.8%). Median total disease duration was 8.3 years in UC group, as well as 6.8 years in CD group. In patients with UC, proctitis was 154 (17.6%), left sided colitis was 410 (47%) and extensive colitis was 309 (35.4%). In CD patients, ileal involvement was found in 297 (43.9%), colonic in 76 (11.2%), ileo-colonic in 299 (44.2%) and isolated upper gastrointestinal involvement in 4 (0.6%) cases. 529 (78.3%) patients had inflammatory disease (non-stenosing non-penetrating behavior), 45 (6.7%) had stenosing behavior, 102 (15.1%) had penetrating behavior, as well as 196 (29%) patients had perianal disease. Mesalazine 658 (75.4%) and thiopurine 397 (45.5%) were the most frequently used conventional treatments for UC, while thiopurine 304 (45%) was most commonly used for CD patients. In the last two-decade, proportion of the biologic usage were 27.9% and 32.1% in UC patients 28.5% and 31.4% in CD patients respectively. Over the three decades, abdominal surgery was 49.2%, 27.8% and 36.3% in CD and colectomy rates was 2.0%, 2.7% and 3.7% in UC patients. While the rate of UC patients has slightly decreased to 98 (61.6%), 401 (58.5%) and 374 (53%) frequency of CD patients has increased to 61 (38.4%), 284 (41.5%) and 331 (47%). Over the course of three decades, there were more UC patients than CD patients, however proportion of UC/CD has been continuously decreased (1.61, 1.41 and 1.13) for three decades respectively. Conclusion: Our study showed that the frequency of UC and CD has significantly increased during the previous three decades in non-endemic era for IBD. While the frequency of UC patients has slightly decreased, that of CD patients has steadily increased over the past three decades. Although the use of biologics has significantly increased, proportions