Medical Imaging

X-ray > Exams & Procedures > Upper GI (or Barium Meal)

The upper GI is an examination used to image the esophagus, the stomach and the duodenum (first part of the small bowel). This examination uses barium to image these structures that would otherwise be invisible.


The UGI examination requires a clean dry upper GI tract, however this can easily be obtained by simply not eating or drinking from midnight the night before your examination, until after your examination is over. We also ask that you abstain from smoking within this time period. Smoking encourages the mucosa (lining) of your throat to produce more mucus than normal. This makes it harder for the barium to coat well and may limit the diagnostic capabilities of the examination.


The UGI 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.

Almost all UGI examinations use gas with the barium to distend the stomach 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.

About the Procedure

The procedure takes about 20 to 30 minutes.

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.

You will first be asked to swallow the gas crystals with a small amount of barium. The radiologist will align the machine so that he or she may examine you while you are swallowing the barium. This is usually done with you standing. After the swallowing has been studied, you will then lie down and roll your body over so that the stomach becomes completely coated for the examination. The examination will continue with the radiologist giving you directional and positional instructions, while periodically taking specific images of the demonstrated anatomy.

Part way through the study you will drink more barium while lying down in order to study your swallowing without the help of gravity. More images will be taken throughout and following this section of the exam. Once the radiologist has obtained the images that he or she requires, the exam is then finished.

At this time, you may change back into your regular clothes and return to your normal activities. The barium will make you feel full until it leaves the stomach. You may eat and drink as you normally would.

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 body, 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.