What it means
It forms where the duct from the liver (common hepatic duct) joins the duct from the gallbladder (cystic duct). It runs behind the pancreas and opens into the duodenum, usually together with the pancreatic duct. A gallstone stuck in it blocks the flow of bile and can cause jaundice, infection or pancreatitis.
For the nurse
After surgery on the bile ducts a T-tube may be left in the common bile duct to drain bile; keep the drainage bag below the level of the wound and record the amount and color of bile.