Endoscopic retrograde cholangiopancreatography is a method to help diagnose intrahepatic and extrahepatic biliary tract abnormalities. In addition, endoscopic retrograde cholangiopancreatography helps diagnose biliary strictures, biliary tract tumors, pancreatic head tumors, examine pancreatic ducts, find the cause of pancreatitis, tumor biopsy, ... and treat biliary tract diseases such as bile duct stones, bile duct tumors, pancreatic diseases such as pancreatic duct stones, pancreatic tumors, ...