Background: The incidence and prevalence of inflammatory bowel disease (IBD) vary between regions but have risen globally in recent decades. A lack of data from developing nations limits the understanding of IBD epidemiology.

Aim: To perform a follow-up review of IBD epidemiology in the Tuzla Canton of Bosnia-Herzegovina during a 10-year period (2009-2019).

Methods: We prospectively evaluated the hospital records of both IBD inpatients and outpatients residing in Tuzla Canton for the specified period of time between January 1, 2009 and December 31, 2019. Since all our patients had undergone proximal and distal endoscopic evaluations at the hospital endoscopy unit, we used the hospital's database as a primary data source, alongside an additional cross-relational search of the database. Both adult and pediatric patients were included in the study. Patients were grouped by IBD type, phenotype, age, and gender. Incidence rates were calculated with age standardization using the European standard population. Trends in incidence and prevalence were evaluated as a 3-year moving average and average annual percentage change rates.

Results: During the 10-year follow-up period, 651 patients diagnosed with IBD were monitored (of whom 334, or 51.3%, were males, and 317, or 48.7%, were females). Of all the patients, 346 (53.1%) had been diagnosed with ulcerative colitis (UC), 292 (44.9%) with Crohn's disease (CD), and 13 (2%) with indeterminate colitis (IC). We observed 440 newly diagnosed patients with IBD: 240 (54.5%) with UC, 190 (43.2%) with CD, and 10 (2.3%) with IC. The mean annual crude incidence rates were found to be 9.01/100000 population for IBD [95% confidence interval (CI): 8.17-9.85], with 4.91/100000 (95%CI: 4.29-5.54) for UC and 3.89/100000 (95%CI: 3.34-4.44) for CD. Calculated IBD prevalence in 2019 was 146.64/100000 (95%CI: 128.09-165.19), with 77.94/100000 (95%CI: 68.08-87.70) for UC and 65.77/100000 (95%CI: 54.45-74.1) for CD. The average annual IBD percentage change was 0.79% (95%CI: 0.60-0.88), with -2.82% (95%CI: -2.67 to -2.97) for UC and 6.92% (95%CI: 6.64-7.20) for CD. During the study period, 24,509 distal endoscopic procedures were performed. The incidence of IBD was 3.16/100 examinations (95%CI: 2.86-3.45) or 1.72/100 examinations (95%CI: 1.5-1.94) for UC and 1.36/100 examinations (95%CI: 1.17-1.56) for CD.

Conclusion: Trends in the incidence and prevalence of IBD in Tuzla Canton are similar to Eastern European averages, although there are significant epidemiological differences within geographically close and demographically similar areas.