Modernization and the Rising Burden of IBD: New Insights From a Global Study

Researchers at the University of Calgary and the Chinese University of Hong Kong propose that inflammatory bowel disease (IBD) progresses through four temporal and spatial epidemiologic stages as it spreads globally.

Traditionally, IBD has been more prevalent in Western countries, with stable or declining incidence rates in recent years. However, the study reveals a significant rise in IBD cases in newly industrialized nations, particularly in Asia, the Middle East, and Latin America. This surge correlates with rapid urbanization, a westernized diet, and environmental changes, suggesting a strong link between modernization and the increasing burden of IBD.

The study introduces a model categorizing countries into four epidemiologic stages of IBD.

• Stage 1, emergence, features low incidence and prevalence.
• Stage 2, acceleration, sees a sharp rise in incidence with still low prevalence.
• In stage 3, compounding prevalence, incidence stabilizes or declines while prevalence increases due to accumulated cases outpacing mortality.
• Stage 4, prevalence equilibrium, occurs when prevalence plateaus as mortality matches incidence in an aging population.

The researchers used 522 population-based studies on the incidence and/or prevalence of IBD across 82 countries, nations, or territories between the years 1920 and 2024.

Low-income countries in Africa, Asia, and Latin America are largely in stage 1, but development may soon push them into stage 2. In these regions, improved diagnostics, training, and population-based studies are needed. Newly industrialized countries (eg, China, Malaysia) are in stage 2 with rising incidence. Countries such as Japan and South Korea are approaching stage 3.

Early industrialized nations (eg, Canada, Denmark, Scotland) are mostly in stage 3 and face challenges managing both young patients and a growing population of aging persons who have IBD, often with comorbidities. Prevalence will continue to rise but may slow over time. Modeling predicts prevalence could reach up to 1.76% in these countries by the 2040s.

“Modelling population demographics enabled us to predict prevalence over the next two decades, while also demonstrating the plateauing of prevalence that characterizes stage 4 (prevalence equilibrium). These data can be used by healthcare systems and society to address the rising global burden of IBD. Furthermore, the testable predictions made by the epidemiologic transition theory that we advance here should serve as a model for future researchers investigating analogous diseases with global, longitudinal epidemiologic data,” the researchers concluded.

Reference

Hracs L, et al. Nature. Published online April 30, 2025. doi:10.1038/s41586-025-08940-0