Preoperative external biliary drainage has been used widely during the past years to decrease the operative mortality and morbidity of patients with obstructive jaundice. However, several controlled studies have reported no benefit from preoperative biliary drainage. The failure to decrease the morbidity and mortality of operations after preoperative biliary drainage coulcl be due to thc persistence of endotoxemia. The porpose af this study, therefore, is to evaluate systemic endotoxemia occur in rats with obstructive jaundice and to determine if there is a change in endotoxemia after oral administration of the bile salts. Experiments using animals showed that the absence of bile salts in the intestinal tract in rats with obstructive jaundice allows endotoxin to be absorbed, and that this absorption can be prevented by the oral aclministration of bile salts.