Bile duct obstruction is not necessarily cancer, there may also be bile duct stones, inflammatory stricture of the bile duct, biliary roundworms, etc. 1. Bile duct stones: This is the most common cause and is caused by intrahepatic bile duct stones, or stones in the gallbladder falling into the bile duct. This can cause obstruction, poor drainage of bile and jaundice. 2. Inflammatory bile duct stenosis: Repeated inflammation of the bile ducts damages the bile ducts, and after repairing the damaged area, scarring will be formed, and the scarring will shrink, which will eventually lead to narrowing of the bile ducts and cause obstruction. 3. Biliary ascariasis: It is mostly caused by factors such as starvation, lowered stomach acid or improper deworming, resulting in roundworms in the intestines burrowing into the bile ducts, which will cause drill-like pain. Ascaris lumbricoides block the bile duct and cause obstruction. When bile duct obstruction occurs, it is necessary to go to the general surgery department or hepatobiliary surgery department or gastroenterology department of the hospital in time to get a clear diagnosis, so as not to delay the condition.