Gilbert syndrome

Bilirubin (total and direct) to document unconjugated hyper-bilirubinaemia; ALP, ALT, AST, GGT to exclude liver disease; FBC with blood film to exclude haemolysis.

If the diagnosis is uncertain the serum bilirubin fasting level can be measured and should exceed the non-fasting level by  > 50%.

This test should not be done during intercurrent illness.

Liver biopsy is not required to establish the diagnosis.