Gastric acid suppression does not promote clostridial diarrhoea in the elderly

Gastric acid prevents bacterial colonization of the stomach and suppression of its secretion might predispose to Clostridium difficile (CD) diarrhoea. We retrospectively studied elderly patients admitted to medical wards of a n acute hospital to determine whether the incidence of CD diarrhoea was gre ater among those previously treated with gastric acid suppressants. From re cords of stool CD toxin tests undertaken in 1995 and 1996, we found 126 cas es with positive results, and selected 126 controls with negative results. Information about pre-morbid illness, predisposing factors for CD and medic ation received in the preceding 16 weeks was obtained from case-notes. A gr eater number of CD positive cases had received antibiotics such as Cefuroxi me, ciprofloxacin or macrolides with or without metronidazole, were more se verely disabled, required assistance for feeding, or had hypoalbuminaemia b efore the onset of diarrhoea. A greater number of controls had received lac tulose, suggesting either that its laxative effect resembled CD infection p rompting frequent stool tests, or that it offered protection against CD in this group. Both groups were similar for the use of proton-pump inhibitors or H2-receptor antagonists, suggesting that susceptible elderly patients ar e not more likely to develop CD diarrhoea after receiving gastric acid supp ression therapy.