Jaundice is a rewarding condition to investigate because an explanation is usually found. A preliminary diagnosis based on the clinical features and liver function tests is made. Specialized investigations are then undertaken. In cholestasis or if the diagnosis is in doubt an obstructing lesion must be excluded. Ultrasonography should be performed first followed by PTC if the ducts appear dilated, ERCP may be the most useful examination in patients whose ducts are normal and in those who have had previous biliary surgery. If either PTC or ERCP fails to demonstrate the biliary system the other should be attempted. Liver biopsy should be performed before submitting an undiagnosed jaundiced patient to surgery.
