This article presents the case of a 56 year-old female patient who was admitted to the surgery ward in order to undergo laparoscopic cholecystectomy. The information obtained through an interview with the patient confirmed a 20-year history of colic pain in the upper right side of the abdomen following dietary transgressions, periodic vomiting, but no fever. The patient did not notice any jaundice. Ten months prior to her admission to the hospital, the patient underwent endoscopy and abdominal ultrasound, which identified the possibility of choledocholithiasis. The patient's lab results were normal and a routine abdominal ultrasound examination confirmed only cholecystolithiasis, no choledocholithiasis, three months prior to her admission to the hospital. Her bilirubin level at the time of admission to the general surgery unit was within the norm. Laparoscopic cholecystectomy was initiated, but following the diagnosis of cholecystoduodenal fistulas, it was converted to an open cholecystectomy, the gallbladder was removed, internal fistulas were supplied, the bile ducts were checked with some stones removed, and a T-drain was inserted. Cholangiography was not performed during the surgery due to equipment malfunction. Post-op recovery was without complication. Cholangiography performed one week after surgery showed residual choledocholithiasis. ERCT and EST were performed and numerous small deposits were removed from the bile ducts. Follow-up cholangiography did not show any choledocholithiasis. Following the removal of the T-drain, the patient was discharged from the hospital in good condition. She has been under observation and does not report any symptoms.