What is a barium enema?
This test is used to take X-rays of the large intestine, which includes the colon and rectum. First, your doctor delivers an enema containing barium through a thin tube that is inserted through the rectum. The solution travels through the rectum and colon, coating the organs. After the solution has been given, air is released through the tube to help the colon expand and make it easier for your doctor to see abnormal growths. A series of X-rays are then taken to reveal images of the colon and rectum.