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Medical Imaging

X-ray > Exams & Procedures > Small Bowel Follow Through

The small bowel follow through is an examination of the small bowel. This examination uses a contrast media (barium) to outline a structure that would otherwise be invisible on X-ray.


The only preparation required for this examination is that you have nothing to eat or drink after midnight the night before your examination until after the examination is over. We also ask that you do not smoke as this increases secretions in your GI tract making it more difficult for the barium to coat the lining well.


The Small Bowel Follow Through exam uses barium for contrast. This 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. The barium used for this examination is fruit flavoured to make it more palatable. Most patients note that it tastes a bit chalky, but otherwise tolerate it very well.

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.

Occasionally the radiologist may wish to use gas with the barium to distend the stomach and/or parts of the small bowel, and to make the barium transparent rather than just solid white. The air is taken in the form of crystals that, when swallowed, bubble and produce air as they dissolve. These crystals are not always used for this examination.

About the Procedure

The amount of time this procedure takes varies greatly, and is dependent upon how long food normally takes to travel through the bowel. Normally, the procedure takes about one and a half to two 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.

Sometimes the radiologist will require a quick look with the fluoroscope before beginning the examination. We usually ask that you start the examination simply by drinking two cups of barium. After about 30 minutes you will be asked back into the examination room where the radiologist will have a look to see how far the barium has traveled through the GI tract. Images will be taken and you will be asked to wait again.

The procedure continues this way, with periodic checks to see the distance the barium has traveled, until the barium reaches the large bowel. At this time the radiologist will take images of what is called the terminal ileum. This is the last 10 to 20 centimeter section of small bowel where it joins the large bowel. After specific images are taken of this area, the procedure is finished and you may continue your normal activities. You may return to your normal eating and drinking habits at this time.

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.