ObjectiveBased on the Global Burden of Disease Study (GBD 2023) database, this study aims to compare the evolution of the disease burden of ulcerative colitis (UC) globally and in China from 1990 to 2023, and to predict the trends for the period 2024 to 2035. MethodsData on the incidence, prevalence, mortality, and disability-adjusted life years (DALYs) of ulcerative colitis (UC), as well as their corresponding rates at both the global level and in China, were extracted to describe their changing characteristics. Joinpoint regression was used to calculate the annual percent change (APC) and average annual percent change (AAPC). Furthermore, a Bayesian Age-Period-Cohort (BAPC) model was applied to project the disease burden from 2024 to 2035.ResultsIn 2023, the global age-standardized incidence, prevalence, mortality, and DALYs rates of UC were 2.87, 44.19, 0.45, and 13.76 per 100 000 population, respectively. Compared with 1990, the global age-standardized incidence rate slightly increased by 6.69%, while the prevalence, mortality, and DALYs rates decreased by 6.81%, 2.17%, and 12.58%, respectively. From 1990 to 2023, the global age-standardized incidence rate showed an upward trend (AAPC = 0.19, 95%CI 0.16 to 0.22). The age-standardized prevalence and DALYs rates exhibited downward trends, with AAPC of ?0.19 (95%CI ?0.23 to ?0.16) and ?0.40 (95%CI ?0.59 to ?0.20), respectively (all P<0.001). The change in the age-standardized mortality rate was not significant (AAPC = ?0.10, 95%CI ?0.44 to 0.25). In China, the age-standardized incidence, prevalence, mortality, and DALYs rates in 2023 were 1.41, 9.50, 0.23, and 5.94 per 100 000 population, respectively. Compared with 1990, the age-standardized incidence and prevalence rates increased significantly by 88.00% and 66.08%, respectively, whereas the age-standardized mortality and DALYs rates decreased significantly by 60.35% and 58.64%, respectively. From 1990 to 2023, China’s age-standardized incidence and prevalence rates demonstrated an upward trend, with AAPC of 1.81 (95%CI 1.69 to 1.93) and 1.20 (95%CI 1.34 to 1.48), respectively (all P<0.001). The age-standardized mortality and DALYs rates showed a downward trend, with AAPC of ?2.60 (95%CI ?3.11 to ?2.09) and ?2.58 (95%CI ?2.79 to ?2.37), respectively (allP <0.001). Notably, the magnitude of these declines in China was greater than that at the global level and across the five Socio-demographic Index (SDI) regions. Projections from the BAPC model indicated that from 2024 to 2035, the global age-standardized incidence rate will remain basically stable, while the prevalence, mortality, and DALYs rates will slowly decrease. In China, however, the age-standardized incidence and prevalence rates will continue to rise, while the mortality and DALYs rates will continue to decline. ConclusionThe mortality and DALYs rates of UC both globally and in China exhibit a downward trend, with a more pronounced decline observed in China. However, the incidence and prevalence burdens of UC in China show an increasing trend and are projected to continue rising over the next decade. Continuous monitoring is required, and more targeted prevention and control measures should be developed in light of the current situation.