Choledochal stone obstruction is the presence of stones in the common bile duct thus blocking it. Bile duct obstruction is a condition in which bile is not drained properly, or is even completely blocked, due to a variety of causes. The bile duct consists of the intrahepatic and extrahepatic portions, and acts as a “water pipe” connecting the liver to the duodenum and draining bile (which is mainly produced by the liver). If the bile ducts become thin or even completely blocked due to problems with the bile ducts themselves or pressure from other tissues around the bile ducts, this can lead to poor bile drainage, which is medically known as bile duct obstruction. In contrast, choledochal stone obstruction is an obstruction of the bile duct caused by a bile duct stone. The incidence of biliary obstruction is high and increases with age, while women are more likely to suffer from the disease than men. The most common cause is gallstones, the prevalence of which ranges from 0.9% to 10.1% in China.