The principle behind the barium enema is quite simple. A contrasting agent is introduced into the rectum, filling the large intestine. Once the barium has reached its destination, X-rays of the colon are taken.
Conventional radiography (X-ray) is usually a simple and painless procedure. The X-ray machine emits a beam of electromagnetic radiation that is aimed at a specific part of the body - the colon, in this case. The resulting image is recorded on film or a computer. The body's tissues vary in density. Each tissue therefore allows a different amount of radiation to pass through. Bones, for example, appear white on X-rays because they are very dense and prevent most of the radiation from passing through to the film. On the other hand, lungs, which are filled with air, allow more of the X-rays to pass through and therefore appear black on radiography images.
The barium enema has many advantages. The procedure is quick, well tolerated and complications are rare. The resulting images are often enough to rule out the need for more sophisticated testing.
What is the purpose of this test?
Barium enemas highlight the colon (right, transverse and left), appendix and rectum, and detect signs of disease or abnormalities. This type of enema is used to identify ulcers, polyps, cancerous tumours and intestinal diseases. The physician may recommend the procedure in light of symptoms presented by the patient. For example, it may be prescribed to those with chronic diarrhea, constipation or irritable bowel and to those who have blood in their stool or who have experienced sudden weight loss.
Prior to the procedure, patients may be asked to take laxatives or to give themselves a cleansing enema to ensure that any remaining fecal material (waste) has been eliminated. Medical centres usually have a specific protocol that must be followed the evening before and the day of the procedure. The requirements specify which laxatives to take, the time at which they should be taken, what foods are allowed, how much liquid to ingest, etc. These instructions are to be followed scrupulously. In cases where patients have not adequately complied with bowel preparation instructions or if preparation was not successful, appointments may be rescheduled. Generally speaking, the following measures apply:
- The list of foods that may and may not be ingested in the 24 to 48 hours leading up to the barium enema must be rigorously followed.
- Foods that are usually allowed include clear broths, fruit gelatin and soft drinks.
- Foods that should generally be avoided are fresh fruits and vegetables, dairy products and products that contain whole wheat.
- Usually, nothing should be taken through the mouth as of midnight the night before the test.
- You can continue to take your prescription medication as usual on the day of the test.
On the day of the appointment, a physician, nurse or radiology technician will administer a barium solution through a tube inserted into the rectum. Once the barium reaches the intestine, it must remain there until the X-rays are taken. The patient will be required to turn several times, as images of all sides of the colon must be taken. The progression of the solution is monitored on a screen. Air may also be injected into the intestine for a complementary set of X-rays tests. After the procedure, the patient is required to drink large quantities of fluids to flush the barium from the system. It is normal for patients to see barium in their stool for a few days after the procedure. Once the barium solution has been administered, it is normal to feel as though you need to defecate. It is also common to experience a feeling of pressure on the abdomen or mild cramps. These symptoms are usually short lived. Patients can resume their regular activities and diet after the procedure. Some people may experience constipation after a barium enema. Although this effect is temporary, speak to your doctor if it persists for a few days.
What to know before going for this test
Before going for a blood test, examination or other, it is always a good idea for you to have a complete list of all prescription or over the counter medications and/or natural products you may be taking. If you are unsure or have any questions, your pharmacist will be able provide you with additional information.
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.