The Full form of CBD is Common Bile Duct. CBD is a small, tube-like structure formed where the common hepatic duct and the cystic duct join. Its physiological role is to carry bile from the gallbladder and empty it into the upper part of the duodenum (the small intestine). The Common Bile Duct is part of the biliary system. Bile is a greenish-brown fluid that helps digest fats from our food intake. It is produced by the liver and stored and concentrated in the gallbladder until it is needed to help digest foods. When food enters the small intestine, bile travels through the CBD to reach the duodenum. Gallstones are hard deposits that form inside the gallbladder when there is too much bilirubin or cholesterol in the bile. Although a person may have gallstones for many years without feeling any symptoms, gallstones can sometimes pass through the CBD, causing inflammation and severe pain. Choledocholithiasis can be caused if a gallstone blocks the common bile duct. Symptoms of Choledocholithiasis include pain in the right side of the abdomen (biliary colic), fever and jaundice. If not diagnosed and treated immediately, Choledocholithiasis can be life-threatening.