ABSTRACT
There is still much to learn about biliary atresia (BA), why it happens and how it happens being good examples of areas where there is too much speculation and not enough hard evidence. The first documented case of BA was reported in English in 1891 by John Thompson. BA is not one disease, certainly not one with a single cause. It seems to be a phenotype resulting from a number of different etiologies. The commonest classification divides BA into three types based on the most proximal level of occlusion of the extrahepatic biliary tree. Extrahepatic cyst formation may be evident and contain clear mucus or bile. That BA is not simply a mechanical obstruction of the biliary tree has been obvious for some time now. There have been a number of studies based on serology in infants with BA that initially suggested a causal link with perinatal viral infection but were later disputed.
