Gallstones are stones that form in the gall (bile). Bile is a watery liquid made by the cells of the liver that is important for digesting food in the intestine, particularly fat. Liver cells secrete the bile they make into small canals within the liver. The bile flows through the canals and into larger collecting ducts within the liver (the intrahepatic bile ducts). The bile then flows within the intrahepatic bile ducts out of the liver and into the extrahepatic bile ducts-first into the hepatic bile ducts, then into the common hepatic duct, and finally into the common bile duct. From the common bile duct, there are two different directions that bile can flow.