[Biliary atresia: a severe illness].

Biliary atresia is a serious disease of unknown cause, affecting newborns. An inflammation and progressive destruction of the bile ducts lead to jaundice, dark urines, and acholia, between the second and sixth weeks of life. Neonatal cholestasis could be due to several different diseases, thus a diagnosis of biliary atresia and early derivation for surgical treatment are necessary to allow a restoration of the bile flow. Eighty percent of the children normalize serum bilirubin after the portoenterostomy (Kasai operation), if they are operated before their 45 days of life. When Kasai operation fails, a liver transplantation is the only possibility. Biliary atresia must be diagnosed before the first month of life and must be considered as a surgical emergency.