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Upper gastrointestinal (GI) series

An upper GI series is an imaging test that uses a contrast medium called barium and x-rays to produce pictures of the upper GI tract. The organs of the upper GI tract include the esophagus, stomach and upper small intestine. It may also be called a barium swallow, if it is looking at the pharynx  during swallowing.

Barium is a chalky, white liquid that coats the inside of the organs and shows their outline clearly on an x-ray. Fluoroscopy imaging is a special type of x-ray that creates a moving image of the barium as it passes through the upper GI tract.

Why an upper GI series is done

An upper GI series may be done to find the cause of symptoms such as:

  • difficulty swallowing
  • vomiting
  • weight loss
  • upper abdominal pain
  • blood in the GI tract

It is also used to:

  • diagnose cancer and other disorders of the upper digestive tract
  • look at the gastrointestinal tract to find any abnormalities
  • find foreign objects that have been swallowed

How an upper GI series is done

An upper GI series is usually done as an outpatient procedure in the x-ray department of a hospital or clinic. This means you won’t have to stay overnight. It takes 20 to 45 minutes to take images of the esophagus and stomach. If the small intestine is being examined, the test can take several hours.

  • If you are breastfeeding or pregnant or think you may be pregnant, tell the x-ray technologist or radiologist before having any type of x-ray.

Getting ready for an upper GI series can vary, but it usually includes:

  • No eating or drinking after midnight the night before the test and until after the test is done.
  • Removing any jewellery and other objects that may interfere with the quality of the x-ray.

During the upper GI series:

  • You may stand in front of the x-ray machine or lie down on an x-ray table, depending on the area being studied.
  • A lead apron may be placed over your pelvic area to protect reproductive organs, depending on the area being studied.
  • Once you are placed in front of the machine or on the table, you will be given the barium liquid to drink. You will be told to stay very still.
  • The x-rays are taken while you swallow the barium and as it moves through the esophagus, then the stomach and the small intestine. You may be asked to hold your breath while the x-rays are being taken.
  • If you are lying on the x-ray table, the table will be raised and tilted different ways to spread the barium.

When the test is finished, you may be asked to wait until the x-rays are developed and the images are clear.

After the upper GI series, you may be given a mild laxative to get rid of the barium and prevent constipation. Your stool (poop) may be white or lighter in colour for a few days after the test. Drinking plenty of fluids after an upper GI series helps to flush the barium from your body and reduces the risk of constipation.

Side effects

On rare occasions, the barium liquid may cause an allergic reaction.

X-rays involve low levels of ionizing radiation, which has the potential to cause cancer and other health problems. The number and complexity of x-rays needed to diagnose and determine the extent of a disease can vary. Even with multiple and repeated x-rays, the total dose of radiation and the associated risk is small.

X-rays are strictly monitored and controlled to make sure they use the smallest amount of radiation possible. The expected benefits of the x-rays must always outweigh any possible risk for the x-rays to be done.

What the results mean

An upper GI series can show:

  • narrowing (strictures) in the esophagus or upper small intestine
  • ulcers in the esophagus or stomach
  • a blockage (obstruction) in the esophagus or small intestine
  • a polyp or tumour in the esophagus, stomach or upper small intestine
  • a problem with the flow of barium into the small intestine
  • tumours in other organs that are pressing on the upper GI tract

What happens if the results are abnormal

Your doctor may recommend more tests, procedures, follow-up care or treatment.

Special considerations for children

Preparing children before a test or procedure can help lower their anxiety, increase their cooperation and develop their coping skills. This includes explaining to children what will happen during the test, such as what they will see, feel and hear.

Preparing a child for an upper GI series depends on the age and experience of the child. Find out more about helping your child cope with tests and treatments.

contrast medium

A substance used in some diagnostic procedures to help parts of the body show up better on x-rays or other imaging tests.

In most cases, contrast medium is injected into or around the structure to be examined.

Also called contrast dye or contrast agent.


A type of high-energy radiation.

The image produced by x-ray.

X-rays are used in low doses to produce images of the inside of the body on film. They are also used in high doses to treat some types of cancer.


The hollow tube in the upper part of the neck that starts behind the nose and mouth and leads to the esophagus (the tube that goes to the stomach) and the larynx (voice box).

The pharynx is made up of the nasopharynx, oropharynx and hypopharynx.

Pharyngealmeans referring to or having to do with the pharynx, as in pharyngeal cancer.

Also called the throat.


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