The most common form is the absence of entire extrahepatic
biliary tree at or above the porta hepatis. This results in the absence of bile
in the stool that typically results in raised conjugated bilirubin and clay
coloured stool. It is essential to differentiate this condition from Idiopathic
Neonatal Hepatitis. Hepatobiliary scintigraphy using imidodicetic acid analogs
is helpful to differentiate these two conditions. This scintigraphy shows good
intake in liver but no excretion in the intestine.