Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
How does the patient prepare for a lower barium enema, and how is it performed?
Any internal or external materials that make an X-ray image less clear can interfere with the accuracy of a barium enema. Therefore, before undergoing a barium enema (lower GI), it is important to eliminate as much fecal material from the colon and rectum as is possible. Prior to the examination, a clear liquid diet and cleansing enemas often are used to empty the colon. Occasionally, further medications that evacuate the bowel may be necessary. External materials such as extra clothing, metallic devices, or jewelry are removed prior to the test. A radiologist (a doctor specializing in the use and interpretation of X-rays) and a radiology technologist work perform the procedure on the patient.
A barium enema involves filling the colon and rectum with a white liquid material (barium) through a catheter (tube) inserted into the rectum through the anus. It is normal during the procedure to feel some fullness or mild discomfort in the abdomen.
Subsequently, an X-ray machine is placed in front of the patient with X-ray film behind.
Images of the colon then are obtained by exposing the abdomen to the radiation. The contrast in density between the barium-filled colon and other structures of the abdomen are apparent on the X-ray film and give an excellent outline of the colon.
The radiologist also will use a fluoroscope, an X-ray device on which the barium can be seen in motion flowing into the colon.
Further static images of the colon then are obtained on plain X-ray film or digital computerized image.
The barium then may be drained so that only a small amount of barium remains sticking to the lining of the colon, and air is infused into the colon to distend it.
Further X-rays then are taken which give more detail of colon's lining than the X-rays of the barium-filled colon. This latter procedure is called a double contrast barium enema since both air and barium are used to provide the images. Polyps and small cancers are more readily found using this technique (called an air contrast barium enema).
A barium enema can take anywhere from fifteen minutes to an hour depending on the problem being studied and the particular anatomy of the patient's colon.