The emergence of inflammatory bowel disease in the Asian Pacific region

Purpose of review: Inflammatory bowel disease has been traditionally considered rare in the Asian Pacific region, but recent evidence indicates that both Crohn disease and ulcerative colitis are becoming increasingly common among local populations. This review will validate this significant epidemiological and clinical observation using data published in the current Asian literature and information presented at the 2004 Asian Pacific Digestive Week in Beijing, China. Recent findings: A progressive rise in the incidence and prevalence of inflammatory bowel disease is discernible is most Asian Pacific countries, more so for ulcerative colitis than Crohn disease. Some ethnic differences are notably evident, as Indians suffer more inflammatory bowel disease than Chinese or Malays. Age of onset and gender are similar to those of Western patients, as are the distribution and extent of disease which, however, tends to be clinically less severe than in European and North American patients. A family history is occasionally elicited, whereas smoking and appendectomy appear to have the same impact on inflammatory bowel disease as seen in the West. A remarkable difference is the absence of any association of Asian Crohn disease with NOD2/CARD15 mutations, as repeatedly observed in white and Jewish populations. Intestinal tuberculosis is still common in the Asian Pacific region, and poses major diagnostic and therapeutic hurdles, often delaying the diagnosis of true Crohn disease. Summary: Investigation of inflammatory bowel disease in the Asian Pacific region offers the unprecedented opportunity to study the 'early stages' of the disease, and may provide new clues to its pathophysiology by identifying key environmental factors and distinct genetic make-ups.