An upper GI and small bowel series is done in a health care office or hospital radiology department.
You may get an injection of a medicine that slows muscle movement in the small intestine. This makes it easier to see the structures of your organs on the x-rays.
Before the x-rays are taken, you must drink 16 to 20 ounces of a milkshake-like drink. The drink contains a substance called barium, which shows up well on x-rays.
An x-ray method called fluoroscopy tracks how the barium moves through your esophagus, stomach, and small intestine. Pictures are taken while you sit or stand in different positions.
The test most often takes around 3 hours but can take as long as 6 hours to complete.
A GI series may include this test or a barium enema.
How to Prepare for the Test
You may have to change your diet for 2 or 3 days before the test. In most cases, you will not be able to eat for a period of time before the test.
Be sure to ask your health care provider if you need to change how you take any of your medicines. Often you can continue taking the medicines you take by mouth. Never make any changes in your medicines without first talking to your provider.
You will be asked to remove all jewelry on your neck, chest, or abdomen before the test.
How the Test will Feel
The x-ray may cause mild bloating but no discomfort most of the time. The barium milkshake feels chalky as you drink it.
Why the Test is Performed
This test is done to look for a problem in the structure or function of your esophagus, stomach, or small intestine.
A normal result shows that the esophagus, stomach, and small intestine are normal in size, shape, and movement.
Normal value ranges may vary depending on the lab doing the test. Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results in the esophagus may indicate the following problems:
You are exposed to a low level of radiation during this test, which carries a very small risk of cancer. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most experts feel that the risk is low compared with the benefits.
Pregnant women should not have this test in most cases. Children are more sensitive to the risks of x-rays.
Barium may cause constipation. Talk to your provider if the barium has not passed through your system by 2 or 3 days after the exam.
The upper GI series should be done after other x-ray procedures, because the barium that remains in the body may block details in other imaging tests.
Caroline DF, Dass C, Agusto O. In: Adam A, Dixon AK, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 6th ed. New York, NY: Churchill Livingstone; 2015:chap 27.
Jenifer K. Lehrer, MD, Department of Gastroenterology, Frankford-Torresdale Hospital, Aria Health System, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.