Low-dose aspirin-induced gastrointestinal diseases: past, present, and future.

Meta-analyses of randomized, placebo-controlled trials of low-dose aspirin indicate that aspirin approximately doubles the risk of major GI bleeding compared with placebo. The risk in Japanese may possibly be higher compared to Western populations, although the evidence is still lacking and prospective studies are required. Prior GI events, older age, and use of other injurious medicines such as NSAIDs, anticoagulants, and corticosteroids seem to be factors associated with an increased risk for upper GI bleeding among aspirin users. Prospective studies are needed to identify specific risk factors for upper GI bleeding in Japanese patients taking low-dose aspirin. There are many potential gastroprotective drugs available in Japan, and studies are needed to assess the relative effectiveness of various strategies including PPI use for the prevention of aspirin-related upper GI ulcer complications and whether any of these other agents also provide protection against small bowel or colonic damage. Aspirin-induced enteropathy is now increasingly being recognized and is presumably not uncommon, and the availability of new imaging techniques for the small intestine and noninvasive tests such as fecal calprotectin should allow rapid progress in this important area.