Biliary atresia is a chronic, progressive liver problem that becomes evident shortly after birth.
Tubes inside and outside the liver, called bile ducts, normally allow a liquid produced by the liver called bile to drain into the intestines and kidneys. Bile aids in digestion and carries waste products from the liver to the intestine and kidneys for excretion. In biliary atresia, bile ducts that are located inside or outside the liver are blocked. When the bile is unable to leave the liver through the bile ducts, the liver becomes damaged and many vital body functions are affected. The cause of biliary atresia is not known.