Bismuth subsalicylate markedly decreases hydrogen sulfide release in the human colon

Background & Aims: Hydrogen sulfide is one of the main malodorous compounds in human flatus. This toxic gas also has been implicated in the pathogenesis of ulcerative colitis. Therefore, a treatment that reduces colonic H2S levels could be clinically useful in the treatment of flatus odor and of ulcerative colitis. In this study the ability of bismuth subsalicylate, a compound that binds H2S, to reduce H2S release in the colon, was tested. Methods: Homogenates made from human and rat feces were incubated with and without bismuth subsalicylate, and gas production was measured. Fecal samples from 10 healthy subjects were analyzed before and after ingestion of bismuth subsalicylate (524 mg four times a day) for 3-7 days. Results: Fecal homogenates showed a dose-dependent relationship between the concentration of bismuth subsalicylate and H2S release. Treatment of subjects with bismuth subsalicylate produced a >95% reduction in fecal H2S release. Conclusions: The ability of bismuth subsalicylate to dramatically reduce H2S could provide a clinically useful means of controlling fecal and/or flatus odor and of decreasing the putative injurious effects of H2S on the colonic mucosa.