Primary sclerosing cholangitis. This inflammation of your bile duct leads to scarring. Doctors don’t know what causes it. Many people who have it also have ulcerative colitis, an inflammation of the large intestine.
Bile duct stones. These are similar to gallstones but much smaller.
Choledochal cysts. Some people are born with a rare condition that causes bile-filled sacs along your bile ducts. Without treatment, they may lead to bile duct cancer.
Liver fluke infection. This is rare in the U.S. but more common in Asia. It happens when people eat raw or poorly cooked fish that’s infected with tiny parasitic worms called liver flukes. They can live in your bile ducts and cause cancer.
Reflux. When digestive juices from your pancreas flow back into your bile ducts, they can’t empty properly.