Best test to differentiative between medical and surgical jaundice is

Investigations for Obstructive Jaundice 1. Serum bilirubin. A normal value is less than 1.0 mg%. Both direct and indirect bilirubin are assessed. Direct is increased in obstructive jaundice, i.e. conjugated hyperbilirubinaemia. van den Bergh's test is done. 2. Serum albumin, globulin and A: G ratio. Normal S. albumin is more than 3.5 gm%. 3. Prothrombin time. A normal value is 12-16 seconds. It is significant if it is more than 4 from the control or more than one and half times the control. It is corrected by injection vitamin K, 10 mg IM OD for 5 days or by FFP--5-10 units. 4. Serum alkaline phosphatase, SGPT, SGOT, 5' nucleotidase. 5. U/S abdomen. 6. ERCP to visualise the site of obstruction, brush biopsy, bile sample for analysis. 7. MRCP--Non-invasive diagnostic tool. Ref: SRB&;s manual of surgery,3 rd ed, pg no 588