Adult patients (≥18 years old) diagnosed with acute calculus cholecystitis who underwent evaluation for possible common bile duct stones by MRCP, EUS, IOC, ERCP, or operative findings. What is the rationale for studyign the requested groups of participants This is a validation study Validation of the 2020 World Society of Emergency Surgery (WSES) Risk Stratification for Common Bile Duct Stones (CBDS) in Patients with Acute Calculus Cholecystitis (ACC):