Abstract
Gall bladder and hepatic bile was sampled from 66 patients undergoing elective operations on the biliary tract. Fifty-one patients had cholesterol gall stones but only 59% of these were found to have bile which was supersaturated with cholesterol. Repeated sampling of hepatic bile from patients with T-tubes showed that the secretion of supersaturated bile was intermittent.These results indicate that it is impossible to separate patients with cholesterol stones from controls simply by examination of the lipid composition of their bile, since an appreciable number of bile samples from patients with cholesterol stones were unsaturated.The fact that cholesterol gall stones form when the bile is supersaturated with cholesterol only intermittently suggests that the gall bladder may also have a part in their formation.