We report a case of cholelithiasis which had serious complications after endoscopic sphincterotomy (EST). An 82-year-old male was admitted to our institution for the treatment of obstructive jaundice resulted from choledocholithiasis. He had carried a history of partial gastrectorr.y for early gastric cancer (II a) and reconstruction of the gastrointestinal tract by Billroth I. Soon after admission, EST was performed; however, lithotomy was failed at that moment. Three days after EST. his condition was impaired very much because of sepsis and DIC. Immediately after endoscopic nasobilary drainage, administration of anticoagulants and antibiotics was carried out. In accordance with improvement of his condition, lithotomy was performed in sufficient manner. As for possible etiology of sepsis occurred, either bending of the common bile duct influenced by gastrectomy in the past or periampullary diverticulum seemed to be major cause. In addition, it might be considered that co-existence of abdominal aortic aneurysm played an important role for development of DIC. We also described the 5 years' bacteriological investigation of the bile from the patients carrying biliary tract disorders experienced in our institution, with special references reported by other investigators. As a result, recent increase of detection rate of Pseudomonas aeruginosa and Enierococcus, which were also found in the bile of this patient, should be noted from view point of chemotherapy.