A barium enema is a type of lower gastrointestinal (GI) x-ray that a doctor can use to diagnose a patient with colon cancer, colorectal polyps or other abnormalities found in the large intestine. If properly performed, it can be a very effective way for doctors to detect cancerous growths in a patient’s colorectal area, especially if the growths are large. Barium enema is also used in monitoring diseases such as Crohn’s disease and ulcerative colitis over time. It is often performed on patients who complain of abdominal pain, blood in stool, unexplained weight loss, diarrhea or constipation.
Although a barium enema X-ray is minimally invasive, patients still need to completely empty their colons before accurate images can be taken by a radiologist.
Although a barium enema X-ray is minimally invasive, patients still need to completely empty their colons before accurate images can be taken by a radiologist. The traditional method of bowel prep is usually the most disconcerting part of any lower GI exam, be it a colonoscopy or a simple x-ray scan. However, it is extremely important in producing the best results of your screen test. Residual fecal matter left in the colon can be mistook for abnormal growths, which may or may not cause unnecessary worry and financial burden.
During bowel prep, patients must adhere to a strict diet 1 or 2 days before their procedure, refraining from any solid foods and consuming laxatives in order to loosen or soften the stool and encourage frequent bowel movements. Bowel prep often results in diarrhea and general weariness, so many patients choose to stay home from work the day before their colonoscopy, endoscopy or barium enema. Oftentimes, doctors ask patients to also take a water enema several times before the procedure to further cleanse the colon.
The difference between a barium enema and a regular abdominal X-ray is that during a barium enema, patients are given a solution containing barium that causes abnormalities in the colon to show up at a higher contrast on the final X-ray image. The result is that a tumor or other growth will show up white on the X-ray image, making it easier to examine. Although the barium solution is extremely useful in the diagnosis process, it also makes bowel prep even more important—the barium solution has no way of distinguishing a growth from a piece of feces and therefore residual fecal matter can show up white on the final image, as well, and produce false-positive results.
The barium solution is extremely useful in the diagnosis process. It also makes bowel prep even more important—the barium solution has no way of distinguishing a growth from a piece of feces and therefore residual fecal matter can show up white and produce false-positive results.
Before a barium enema X-ray is taken, the barium contrast solution is inserted via a small latex tube through the patient’s anus. The patient usually is not sedated for this process, since it is only minimally uncomfortable.
Generally, there are two main types of barium enema X-rays: a single contrast study and a double contrast study. During a single contrast study, the entire colon is filled with the barium solution and then images are captured, so doctors can see large growths along the large intestine. Sometimes, a balloon-like device is attached to the end of the enema to keep the solution from leaking out while the X-ray is being taken. You may be asked to move around to help the barium solution flow to different sections of the colon while images are taken at multiple angles.
In a double contrast study, also known as an air contrast study or a double contrast barium enema, the barium solution is pumped through the colon and then the entire colon is drained, leaving a thin, residual layer of barium solution lining the colon wall. Then, air is pumped through the rectum, inflating the colon for better viewing. The double contrast barium enema is actually more detailed and can detect abnormalities that would otherwise be more subtle, such as inflammatory bowel disease (IBD), slight bowel narrowing or diverticulitis. The test detects approximately 30-50 percent of gastrointestinal diseases usually found during a regular colonoscopy procedure. Unfortunately, the process of inflating the colon with air is often reported to be quite uncomfortable for patients. The double contrast barium enema also takes more time to perform and is therefore not the preferred method for some patients. In many cases, especially with older patients, a single contrast barium enema will suffice. Neither of these procedures is a sensitive or specific as colonoscopy, which remains the gold standard for diagnosis of colon polyps and cancers.
After the barium enema procedure, you will need to use a restroom or a bedpan to try and remove as much of the leftover barium solution as possible. Additional images after you attempt to re-empty your colon might be taken, as well. The entire process takes anywhere between half an hour and an hour. However, the actual solution is only held inside your body for 15 minutes. For the next few days, you’ll need to drink plenty of liquids to try and flush out the barium from your system. Your stool might appear white or pink during this time period, which is completely normal. It is more important to pass the remaining barium in a timely manner, so that it does not have time to harden and cause constipation or obstruction. Other than the rare complications that can arise from residual barium, the risks of a barium enema are quite minimal.
Contact one of our colonoscopy specialists if you would like to screen for colon cancer, diverticulosis or other GI conditions with a barium enema. Test results are usually available within a couple days after the test. Other advantages include the lack of need for sedation and the relatively short duration of the procedure. However, please keep in mind that other tests, such as colonoscopy, may be necessary if you show abnormalities, as barium enema is limited in its ability to detect colon polyps and other growths.
Reviewed 12/12/2011 by David M. Nolan, M.D.
Diplomate of the American Board of Internal Medicine, 2011
Currently a Fellow of Gastroenterology, at UCI 2011-2014