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Upper gastrointestinal (GI) series

An upper GI series is an imaging test that uses a contrast medium (barium sulphate) and x-rays to produce pictures of the upper GI tract. The upper GI tract includes the esophagus, stomach and upper small intestine.

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

An upper GI series is also called a barium swallow.

Why an upper GI series is done

An upper GI series may be done to:

  • examine the upper GI tract
    • A barium swallow studies swallowing, the pharynx and the esophagus. It may be done separately or as part of an upper GI series
    • An upper GI series studies the esophagus, stomach and upper small intestine.
  • find the cause of symptoms, such as:
    • difficulty swallowing
    • vomiting
    • weight loss
    • upper abdominal pain
    • bleeding into the GI tract
  • diagnose cancer and other disorders of the upper digestive tract

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. It takes 20–45 minutes to take images of the esophagus and stomach. A follow-through study of the small intestine can also be done, which can take several hours.

  • It is important for women to tell the x-ray technologist or radiologist if they are breast-feeding, pregnant or think they may be pregnant before having any type of x-ray.
  • Preparation 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.
  • The person will be asked to remove clothing, jewellery and other objects that will be in the x-ray field and may interfere with the quality of the x-ray.

During the upper GI series:

  • Depending on the area being studied, the person stands in front of the x-ray machine or lies on an x-ray table.
  • A lead apron may be placed over the pelvic area to protect reproductive organs, depending on the area being studied.
  • People are asked to stay very still and may be asked to hold their breath while the x-rays are being taken.
  • X-rays are taken while the barium is being swallowed and as it moves through the esophagus, then the stomach and the small intestine.
  • The x-ray table is raised and tilted different ways to spread the barium.
  • The person may be asked to wait until the x-rays are developed and the staff is sure that the images are clear.

After the upper GI series, a mild laxative may be needed to get rid of the barium and prevent constipation.

  • The person’s stools may be white or lighter in colour for a few days following the test.
  • Drinking plenty of fluids after the procedure helps to flush the barium solution from the body and helps to prevent constipation.

Potential side effects

X-rays involve low levels of ionizing radiation, which has the potential to cause cancer and other defects. 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.

On rare occasions, the contrast dye may cause an allergic reaction.

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 a change or abnormality is found

The doctor will decide whether further tests, procedures, follow-up care or additional treatment are needed.

Special considerations for children

Being prepared for a test or procedure can reduce anxiety, increase cooperation and help the child develop coping skills. Parents and caregivers can help prepare children by explaining to them what will happen, including what they will see, feel and hear during the test.

The preparation you can provide for an upper GI series depends on the age and experience of the child. See the following for more age-specific information on helping children cope with tests and treatment.

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.


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