Bilirubin may be present in the urine when bile duct obstruction, liver disease, or liver damage is present. Bilirubinuria can be detected before other clinical symptoms, such as jaundice, are present or recognizable. The detection of small quantities of bilirubin is very important in early diagnosis of obstructive and hepatic jaundice.
The urine bilirubin test is also useful in the differential diagnosis of obstructive jaundice (positive for bilirubinuria) vs. hemolytic jaundice (negative for bilirubinuria).