In an experiment mimicking a severe surgical trauma by deliberate renal ischemia, the postoperative outcome in jaundiced rats was studied. Intervention studies were performed with preoperative oral lactulose (to reduce endotoxin toxicity) or preoperative internal biliary drainage. Compared to control, obstructive jaundice in rats significantly reduced survival time (p less than 0.001) and enhanced renal impairment (p less than 0.001) after renal ischemia. Preoperative supportive therapy of jaundiced rats with oral lactulose increased survival time (p less than 0.01) but did not reduce deterioration of renal function. Preoperative internal biliary drainage proved to be superior, with a significant reduction of renal impairment (p less than 0.001) and an improved survival time (p less than 0.001). Our experiments provide further evidence that obstructive jaundice increases the complication rate following major surgical procedures. Based on our results in rats, we suggest that in obstructive jaundice preoperative internal biliary drainage is the supportive therapy of choice. However, if adequate drainage is not possible, oral treatment with lactulose may help reduce postoperative complications.