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Medical Imaging

X-ray > Exams & Procedures > Small Bowel Enema

The small bowel enema is an examination of the small bowel. It allows the radiologist to control the rate at which the contrast media (barium) travels, allowing them to closely examine the entire length of bowel.


Two types of contrast are used for this examination: barium and methyl-cellulose.

Barium is an element from the periodic table that is suspended in water. It has a high atomic number that makes it difficult for X-rays to pass through; making filled or coated structures that would otherwise be invisible show up on the X-ray images.

Barium is an inert substance. This means that it enters and exits the body in the same form. It does not interact with nor is it metabolized by the body making it a very safe and effective contrast media.

Methyl-cellulose is a non-digestible vegetable fiber. This adds volume to the contrast but also dilutes the barium in the bowel and makes it transparent, allowing the radiologist to see the wall of the bowel and interior.

About the Procedure

The procedure takes about one and a half hours.

When you arrive the day of your examination you will be escorted to an area where you can change your clothes. You will then be taken into the examination room where the procedure will take place. During the examination there will be two other people present: a technologist and a radiologist. The technologist will ensure your comfort and safety throughout the procedure and make sure that the equipment functions properly. The radiologist carries out the fluoroscopy. Fluoroscopy uses radiation just like conventional X-rays, but it is similar to a movie rather than a snap shot.

St. Michael's Hospital is a teaching facility and there may be a student technologist or radiology resident present for your examination. These students are highly trained and closely supervised to provide you with the best care while maximizing their education.

At first the radiologist will give you an injection of a drug called metoclopramide. This drug is designed to speed up the action of the small bowel so that the contrast can travel through quickly.

The procedure then requires the introduction of a small diameter flexible tube into the small bowel. This tube will usually be passed through the mouth (although sometimes the nose) down the esophagus, through the stomach and into the first part of the small bowel called the duodenum.

This is the most difficult part of the procedure. Most patients tolerate this well because the radiologist will freeze the throat with a special spray, so that passing the tube is more comfortable for you. In some cases your radiologist may choose sedation if necessary. Once the tube has passed the throat and is in the stomach, the radiologist uses the X-ray to guide the tube into the duodenum. This part of the procedure can be difficult for the doctor at times and can take a few minutes but you should feel very little throughout.

Once the tube is in place, you simply lie quietly while the radiologist controls the rate at which the barium flows through the bowel, and takes images throughout. Once the doctor has all the images required, and the barium has reached the large bowel, the procedure is over.

We ask that you drink eight to ten glasses of water a day for the two days following your procedure to help clear the barium out of your bowel, as it can lead to constipation.

The radiologist has only had a preliminary look at the images. They will need more time to examine the images before a diagnosis can be made, and the report sent to your doctor.