Biliary atresia factsheet


Biliary atresia is a rare liver condition that happens in newborn babies. It causes scars in the liver, which block the bile ducts. 

Bile ducts are tubes that connect organs like the liver and gallbladder. These tubes carry bile, which is a liquid that helps digest food. 

When bile cannot drain because of the scarring, it builds up in the liver and causes damage.

Biliary atresia is rare, and doctors do not know what causes the condition. Some babies with biliary atresia can also have other issues with their organs.

 Signs and symptoms

Signs and symptoms of biliary atresia usually develop 4 – 8 weeks after birth and are usually caused by a buildup of bilirubin. 

Bilirubin is a substance found in bile. It is yellow and is made when red blood cells are broken down.

Signs of biliary atresia include:

  • jaundice: when the skin and whites of the eyes look yellow
  • dark urine: dark yellow or brown-coloured urine can indicate there is too much bilirubin in the blood
  • pale, clay or grey-coloured poo: bilirubin and bile give poo its dark colour, so a lighter-coloured poo can mean bilirubin is not being passed through the body properly.


Biliary atresia can have symptoms that are similar to other liver conditions.

Your child’s doctor will do tests and scans to check the liver and rule out other health conditions.

This can include:

  • blood tests
  • urine tests
  • ultrasound scan of the liver
  • cholangiogram - a test that looks at the flow of bile through the liver
  • liver biopsy – where a piece of tissue is taken from the liver and tested. 


Biliary atresia is treated with surgery as early as possible. The procedure used is called a portoenterostomy or a Kasai procedure.

This procedure removes the blocked bile ducts and connects the liver directly to the small intestine. This will let the bile drain away from the liver. 

Most babies will recover well after this procedure and may not need other treatments as they grow up.

Some babies do not have good bile flow after surgery or continue to have liver problems. When this happens, they may need a liver transplant.

A liver transplant is a procedure that involves:

  1. removing the liver that is not working properly
  2. replacing the liver with a healthy liver donated by another person.

Biliary atresia is the most common reason for liver transplants in children.

Babies with biliary atresia will continue to see their treatment team as they grow up, even if they are healthy. The treatment team will check:

  • their growth and development
  • their nutrition
  • any other health issues that may develop.



Cholangitis is a life-threatening infection of the bile ducts in the liver. It is common after the Kasai procedure and can cause a baby to become very sick very quickly.

Cholangitis is caused by bacteria moving from the bowel to the liver. 

Symptoms can include:

Cholangitis is treated with antibiotics in the hospital. 

If your baby shows signs of cholangitis after the Kasai procedure, go to your nearest emergency department as soon as possible, or call Triple Zero (000) for an ambulance. 

Failure to thrive

Failure to thrive is a diagnosis given to babies that are not growing or putting on weight like they should be for their age.

When bile does not drain properly, the body can have trouble digesting fat. This means your child may not get enough of certain vitamins and minerals.

Your child’s treatment team will talk to you about vitamins, minerals and special infant formula for babies recovering from biliary atresia.

Cirrhosis of the liver

Cirrhosis of the liver is scarring on the liver that happens after long-term illness and damage. Cirrhosis of the liver can stop children from growing and developing as they should.

Portal hypertension

Portal hypertension is a condition where there is high blood pressure in the portal vein. The portal vein is a central vein that drains blood from other organs to the liver. 

The blood vessels can become tight when the liver is scarred from damage or disease. This makes it hard for blood to flow through and increases the pressure in the veins, including the portal vein.  

High pressure in these veins can cause:

  • the spleen to get bigger 
  • ascites – excess fluid in the belly which causes bloating
  • varices – swollen veins that can bleed into the digestive system.

If your baby has dark or black-coloured poo and blood-stained vomit, they may have varices that are bleeding.

If this happens, call Triple Zero (000) for an ambulance or go to your nearest emergency department as soon as possible.

Last updated Wednesday 6th March 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024