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 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. 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.

An upper GI series is also called a barium swallow. A barium swallow studies swallowing, the pharynx and the esophagus. It may be done separately or as part of an upper GI series.

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.

You can't eat or drink anything after midnight before the test and until after the test is done.

Before you have an upper GI series, it is important to tell the x-ray technologist or radiologist if you are pregnant, think you may be pregnant, or if you are breastfeeding.

You 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:

  • 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 place 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.
  • The x-ray table is 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 bowel movements (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

X-rays use low levels of ionizing radiation. Ionizing radiation is strong enough to damage cells in our bodies and increase the chance of developing cancer. X-rays are strictly monitored and controlled to make sure they use the least possible amount of radiation. Even with multiple and repeated x-rays, the total dose of radiation and the associated risk is small. The benefits of having an x-ray outweigh the risk of exposure to the small amount of radiation received during the scan.

On rare occasions, the barium liquid 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 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 treatment.

Expert review and references

  • Donna Maziak, MD, MSc, FRCPC
  • American Cancer Society. Imaging (Radiology) Tests. Atlanta: American Cancer Society; 2010.
  • X-Ray (Radiography), Upper GI Tract. American College of Radiology and the Radiological Society of North America. RadiologyInfo. Oak Brook: Radiological Society of North America, Inc; 2010.
  • Upper GI Series (Gastrointestinal series). Children's Hospital Boston. Children's Hospital Boston - My Child Has.... Boston, MA: Children's Hospital Boston;
  • Upper GI. Cincinnati Children's Hospital Medical Center. Cincinnati Children's Hospital Medical Center - Your Child's Health. Cincinnati, OH: Cincinnati Children's Hospital Medical Center; 2010.
  • Dollinger M, Ljung BM, Morita ET, Rosenbaum EH . How cancer is diagnosed. Ko AH, Dollinger M, Rosenbaum E. Everyone's Guide to Cancer Therapy: How Cancer is Diagnosed, Treated and Managed Day to Day. 5th ed. Kansas City: Andrews McMeel Publishing; 2008: 2:17-30.
  • Fischbach F. & Dunning MB. Manual of Laboratory and Diagnostic Test. 9th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2009.
  • Upper GI and small bowel series. National Cancer Institute & National Library of Medicine. MedlinePlus: Trusted Health Information For You: Medical Encyclopedia. Bethesda, MD: National Cancer Institute & National Library of Medicine; 2010.
  • Vogel WH . Diagnostic evaluation, classification and staging. Yarbro CH, Wujcki D, Holmes Gobel B (eds.). Cancer Nursing: Principles and Practice. 7th ed. Sudbury, MA: Jones and Bartlett; 2011: 8:166-197.

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