What is biliary atresia?

Biliary atresia is a condition in newborn babies in which bile is blocked from moving from the liver to the small intestine.

Bile is a substance that is made and released by the liver. From the liver, it moves through a network of tube-like structures called bile ducts to the small intestine, where it helps the body break down and absorb food.

In children who have biliary atresia, the bile ducts are blocked because of damage and scarring. As a result, bile can’t flow to the small intestine. Instead, it builds up in the liver and damages it.

Who is affected by biliary atresia?

Biliary atresia is a relatively rare condition (approximately 12,000 cases a year in the United States).

What are the causes of biliary atresia?

The causes of biliary atresia are not known, but may include:

  • Inflammation (swelling) and scarring caused by problems with the immune system
  • Infection by a virus
  • Exposure to harmful chemicals
  • Mutations (changes) in the genes. (Biliary atresia is not inherited from the baby’s parents.)

What are the symptoms of biliary atresia?

The first sign of biliary atresia is jaundice (skin and eyes appear yellow), a condition in which there is too much bilirubin in the blood. Bilirubin is a substance produced when red blood cells break down. Although most newborns have some degree of jaundice in the first week of life, if it is still present after two weeks, it should be checked out by a doctor.

Other signs and symptoms of biliary atresia include:

  • Light beige stools (Normal stool color for infants is yellow, green or brown.)
  • Dark brown urine
  • A swollen belly (as the liver and spleen grow)
  • Difficulty gaining weight
  • Ascites (fluid in the belly)
  • Liver failure after several months if the biliary atresia is not treated

Last reviewed by a Cleveland Clinic medical professional on 03/06/2019.


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