Fecal hydrogen sulfide production in ulcerative colitis

OBJECTIVE: Sulfide, a product of sulfate-reducing bacteria, has been proposed to play an etiologic role in ulcerative colitis. Ulcerative colitis feces have increased numbers and activity of sulfate-reducing bacteria, but only modestly increased sulfide. However, fecal sulfide exists largely in the volatile, highly toxic H2S form that moves rapidly from feces to surrounding gas. Our aim was to quantify the fecal release of H2S and other volatiles (CO2, H2, CH4, methanethiol, and dimethylsulfide). METHODS: Fecal samples from 25 subjects with ulcerative colitis and 17 controls were incubated in 4-L containers, and gas release was assessed at intervals over 24 h. RESULTS: H2S release by ulcerative colitis feces was elevated 3-4-fold at every measurement point compared with normal feces (p