Helicobacter pylori in cathartic stools of subjects with and without cimetidine-induced hypochlorhydria.

We previously identified viable Helicobacter pylori in stools from asymptomatic hosts. We now report whether a decrease in gastric acidity enhances faecal shedding. Sixteen asymptomatic H. pylori-positive patients underwent two separate days of phosphosoda-induced diarrhoea, both with normal gastric acidity and under hypochlorhydric conditions induced with the H2-blocker cimetidine. Stool samples were collected for culture to determine the presence of viable H. pylori. Five of the 16 patients gave positive cultures with at least one stool from both normal pH and cimetidine-induced hypochlorhydria. Four were negative for all samples with both. Six gave positive stools only after cimetidine treatments, while one gave positive samples with normal pH but not with cimetidine (two-tailed P value, 0.13; McNemar test). These numbers show a trend suggesting that cimetidine-induced hypochlorhydria increases shedding of viable H. pylori.