My Son Had Elevated Liver Enzymes ALT/AST/ALP And Direct Bilirubin.

My son had elevated liver enzymes ALT/AST/ALP and Direct Bilirubin. He is 11 years old. He was given Ursodial and his direct bilirubin levels have went from 4.0 to 3.0 to 1.8 and now is currently at .8. He's ALT is still at 80, but the other levels are normal. We have not heard any cause for his condition. They have requested for us to stop taking Ursodial. Is this to monitor his levels without medication because they do not have a cause? His levels were 400 ALP, 200s for ALT and AST initially.