If necessary, biopsies can be taken with these techniques.More advanced endoscopic testing to look for obstruction of the biliary or pancreatic ducts is called an endoscopic retrograde cholangio-pancreatography or ERCP. This test is performed like an EGD except that during the test dye is injected into the bile and pancreatic ducts to look with X-rays for obstruction of the ducts.Other imaging stu