There is a long-pending question if the clinical concept of the "postcholecystectomy-syndrome" should be eliminated from the medical literature and medical praxis. To answer this question, the pathophysiological aspect of bile acid metabolism was investigated. Total bile acid level and basic bile acid concentration in blood serum and bile were estimated in the clinical course of 45 patients with cholelithiasis before and after cholecystectomy. In these patients, the endogenous bile acid tolerance test following intramuscular administration of 20 micrograms of caerulein was also performed. These patients were divided into two groups, i.e. patients with the postcholecystectomy syndrome and those without the syndrome. The postoperative clinical course was observed for at least one year. In both groups, the results of clinical examinations were compared. Based on the results of these investigations, it should be stressed that the derangement of bile acid metabolism contributes to the pathogenesis of the postcholecystomy syndrome, and that this clinical concept must be admitted in practice, although the pathophysiology of this disorder has not been clarified in detail.