The trajectory of inflammatory bowel disease in east and southeast Asia: transitioning from acceleration in incidence to compounding prevalence.

The epidemiology of inflammatory bowel disease (IBD) progresses through four stages: emergence (stage 1), acceleration in incidence (stage 2), compounding prevalence (stage 3), and prevalence equilibrium (stage 4). Most early industrialised regions (Europe, North America, and Oceania) have reached stage 3, whereas many newly industrialised regions-those that predominantly industrialised after World War 2-are in stage 2, for which rising incidence presents a growing public health concern. The newly industrialised east and southeast Asia region encompasses countries and territories both on the verge of transition between stages 1 and 2 and those poised to become the first non-early industrialised regions to enter stage 3. This Review traces the 100-year trajectory of IBD in five regions (Japan, South Korea, China, Hong Kong, and Malaysia) of east and southeast Asia, from the first reported cases in 1920s Japan to the present day, with each region currently in the early, middle, or late phase of stage 2, highlighting IBD's epidemiological evolution. Understanding cross-regional epidemiological trends is essential for developing interventions to address the rising burden of IBD globally. East and southeast Asia's experiences can serve as a model for other newly industrialised and emerging regions anticipated to follow a similar trajectory in the coming decades.