Epidemiology and temporal trends of adult inflammatory bowel disease in Taiwan

Background: Despite industrialization and advances in healthcare, the prevalence of inflammatory bowel disease (IBD), which encompasses Crohn's disease (CD) and ulcerative colitis (UC), is increasing in Taiwan. Population-based studies can estimate the incidence or prevalence of IBD; however, there is a lack of information regarding the disease phenotype. Therefore, this study was designed to investigate the epidemiologic trends of IBD in Taiwan to gain a more comprehensive understanding. Methods: Patient data were reviewed from a prospectively registered study by the Taiwan Society of IBD (TSIBD). Results: We collected data from 2752 patients with IBD, of whom 881 had CD and 1871 had UC. Their average age was 41.99 ± 15.19 years. The CD group had more male patients than the UC group (67.88% vs. 60.72%; p < .001). The rates of appendectomy, bowel resection, and surgery for perianal disease before IBD diagnosis, along with the increased use of steroids, immunomodulators, and biologics, were higher in the CD group. From 2005 to 2023, the ratio of UC to CD cases in Taiwan decreased, the proportions of patients with colonic and penetrating CD also declined, and the proportion of patients with UC exhibiting ulcerative proctitis increased. Conclusion: In Taiwan, similar to high-income countries, the ratio of UC to CD cases has declined. The reduced of colonic and penetrating CD indicates that diagnostic awareness has improved and colonoscopic examination has become more comprehensive in Taiwan.