Hi, Thanks for choosing healthcaremagic. ERCP is a study to evaluate the CBD and to assess whether any stone is there within it. That will change the course of the management and the surgery which they do. As you have high bilirubin there are chances that a stone is stuck in the CBD. With ERCP they can remove the stone also. CBD stones are very difficult to detect on USG. Only dilated CBD can be seen on ultrasound which is an indirect evidence of CBD stone. I think you should undergo an ERCP as it will clear the stones from the CBD and then go for surgery for removal of GB which will remove all stones from your biliary system. Another alternative for ERCP is MRCP which is done using MRI. The advantage in ERCP is that if they find a stone they can remove it simultaneously but in MRCP if stone is detected you have to undergo ERCP/open surgery to remove the stone. So in your case, ERCP should be more useful. Hope it sorts your problem and wishing you a speedy recovery. Regards, Dr. Pankaj Nagori Specialist Radiologist