What is biliary atresia?
Biliary atresia occurs when the pathways (ducts) that move bile from the liver to the intestines are not formed properly or become blocked. This blockage prevents bile from draining from the liver to the intestines. When bile cannot drain from the liver, it builds up inside the liver and causes damage.
If biliary atresia is identified in the early stages of the disease, infants can undergo surgical treatment sooner. Having surgery sooner gives infants the best possible outcome.
What is bile and how does that relate to stool?
Bile is a dark green to yellowish digestive fluid that is made in the liver and flows into the intestines. It then leaves the body in the stool.
Bile is what makes stool darker. When bile cannot get into the intestine, the stool appears pale.
Screening for biliary atresia in Ontario
- In January 2023, Newborn Screening Ontario launched a provincial program for biliary atresia screening.
- Parents/caregivers are the primary screeners and will use an Infant Stool Colour Card (ISCC) given to them by the birth hospital or midwifery group to monitor the colour of their infant’s stool.
- At home, parents/caregivers should use the ISCC to compare their infant’s stool colour to the pictures on the card during regular diaper changes for the first month of life.
- If your baby was born early, at less than 37 weeks, monitor their stool for a longer period, until one month past your expected due date.
- If your infant’s stool is pale, there may be a problem, and you should contact Newborn Screening Ontario through the contact methods found on the Infant Stool Colour Card for further support or via their online contact form.
For more details about the screening program, and your role as a parent or caregiver, please visit the Newborn Screening Ontario website. The website has a section dedicated to frequently asked questions and an infographic reminder for parents and caregivers on how to screen.
Why screen for biliary atresia?
Currently, most babies with biliary atresia are not being diagnosed early enough to give them the best possible outcomes. Monitoring the colour of your infant’s stool can help identify potential problems sooner, leading to earlier diagnosis and treatment.
Signs and symptoms of biliary atresia
Early signs
- Jaundice lasting longer than two weeks of age (yellowish skin and eyes)
- Pale stool
- Darker-coloured urine
Late signs
- Failure to thrive (slower weight/height growth)
- Enlarged abdomen (ascites)
- Enlarged liver and spleen (hepatosplenomegaly)
- Gastrointestinal (GI) bleeding
How common is biliary atresia?
Biliary atresia affects approximately 1 in 17,000 infants per year in Ontario. About eight new cases of biliary atresia are diagnosed in Ontario every year.
What causes biliary atresia?
The exact cause of biliary atresia is not yet known, and research is currently underway to learn more. Currently, it is believed to occur due to a combination of genetic and environmental factors.
How is biliary atresia diagnosed?
If your infant’s stool is pale, your infant should be assessed. Pale stool means there might be a problem, including an increased risk of biliary atresia.
Stool screening with the infant stool colour card is not a diagnostic test. There are several reasons stool may be pale in colour and several causes for bile to build up in the liver (cholestasis). To make a diagnosis, your child’s health-care provider will need to run diagnostic tests, such as blood tests and imaging of the liver.
Treatment of biliary atresia
Biliary atresia is treated with a surgery called the Kasai procedure. In this procedure, the blocked bile ducts are removed, and a piece of the small intestine is directly connected to the liver in place of the bile duct. This allows bile to leave the liver and enter the intestine. When the Kasai procedure is successful, the stools become yellow or brown, jaundice improves and nutrition and well-being improve. The Kasai procedure has better success rates if done before 30–45 days of age. Even with the Kasai procedure, some children will still develop more scarring in the liver and eventually need a liver transplant.
Infants diagnosed with biliary atresia after 3-4 months of age already have cirrhosis and do not have a Kasai procedure. These infants will require a liver transplant.
Complications of biliary atresia
When bile cannot leave the liver, it builds up inside, which leads to liver damage. This liver damage includes scarring and loss of liver function. Without treatment, infants with biliary atresia will develop severe scarring (cirrhosis) by 6 months of life.
Cirrhosis
Cirrhosis is a progressive condition and gets worse over time. The liver continues to break down until it is no longer able to work normally. Cirrhosis can eventually lead to complications such as high blood pressure in the portal vein, a condition called portal hypertension. The portal vein is the blood vessel that carries blood from the intestines to the liver.
Portal hypertension
Portal hypertension can lead to other complications, including ascites, which is a build-up of fluid in the abdomen. Portal hypertension can also lead to enlarged blood vessels (varices) in the stomach and/or esophagus. Varices can break down and cause life-threatening bleeding.
Without treatment, these complications will lead to liver failure in infants with biliary atresia by the age of 1 year. Infants with liver failure will need to have a liver transplant. Identifying and treating biliary atresia early can help slow down and prevent the development of these complications.
What should I do if I see pale stool?
If your infant has a pale stool, contact Newborn Screening Ontario using the contact methods on the infant stool colour card.
- A Newborn Screening Ontario team member will contact you by the next business day to discuss the concern and conduct a telephone assessment.
- If required, the team member will refer your infant to a GI specialist (gastroenterologist) at one of the five paediatric academic health centres in Ontario.
If you live outside of Ontario and have concerns about your infant’s stool colour, contact your health-care provider.
When to see a doctor for pale stool
The Newborn Screening Ontario team member will only be able to help you with concerns about the pale colour of your baby’s stool. If you have any other concerns about your baby, other than stool colour, you should contact your health-care provider.
References
Canadian Liver Foundation. (2022). Biliary atresia. Retrieved from: https://www.liver.ca/patients-caregivers/liver-diseases/biliary-atresia/
National Institute of Diabetes and Digestive and Kidney Diseases. (2017). Biliary atresia. Retrieved from: https://www.niddk.nih.gov/health-information/liver-disease/biliary-atresia/definition-facts#cirrhosis
Newborn Screening Ontario. (2023). Biliary atresia. Retrieved from: https://www.newbornscreening.on.ca/en/biliary-atresia-screening/overview