Hi, Bilirubin is tested when people have jaundice or your Dr. suspect about liver or gallbladder problem. The test requires fasting for 4 hours. Some drugs can make it elevate too. So first of all you discuss with your doctor see any chance the drug you're taking interferes the test. If so, there might be some other tests. Quite a few diseases can lead to higher bilirubin, including hepatitis, Gilbert disease, gallstones, narrowing bile duct, etc.