Gallstones, obesity, and jejunoileostomy.

An attempt has been made to identify the causes of increased cholesterol gallstone formation in obese patients both before and following jejunoileostomy. The prime lithogenic mechanism in obesity seems to be increased cholesterol mobilization and excretion in the bile. In jejunoileal bypass, a host of factors, including possible limited bile salt synthesis, increased bile salt loss, and bacterial alteration of bile acids, along with the effects of rapid weight loss, may play a role. The identification and understanding of these factors will be important if attempts at prevention by administratin of antibiotics to reduce bacterial overgrowth, or by giving chenodeoxycholic or ursodeoxycholic acid to replenish the diminished bile acid pools, are to be carried out.