<prompt> A 56 year old man presents to his internist with jaundice. The patient is receiving no medication and his only symptomatic complaints is mild fatigue over the past 2 months. Physical examination is remarkable only for the presence of scleral icterus. The patient has no significant past medical history. Analysis of serum chemistry reveals the following: SGOT : 0.58 microkatL 35UL SGPT : 0.58 microkatL 35UL Total bilirubin : 91.7 micron molL 7 mgdL Direct Bilirubin : 85.5 micron molL 5mgdL Alkaline phosphatase:12 micron katL 720UL Which of the following is the next appropriate diagnostic step?UltrasoundLiver biopsyReview of peripheral blood smearEndoscopicretrograde cholangiopancreatography ERCP  <response>: Answer is A Ultrasound: Initial investigation of choice in a case of obstructive jaundice is: ULTRASONOGRAPHY The patient in question has an obstructive form of jaundice, as is indicated by marked elevation of conjugated hiliruhin together with a significant rise is Alkaline phosphatase. Patient: should therefore be next subjected to ultrasonography to confirm the diagnosis and if possible locate the site of block. 