Alternative names: GI series; Barium swallow x-ray; Upper GI series
Definition: An upper GI and small bowel series is a set of x-rays taken to examine the esophagus, stomach and small intestine.
Barium enema is a related test that examines the large intestine.
How the Test is Performed
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 (480 to 600 millilitres) 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 three hours but can take as long as six 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 two to three 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:
- Esophageal cancer
- Esophageal narrowing (stricture) – benign
- Hiatal hernia
Abnormal results in the stomach may indicate the following problems:
- Gastric cancer
- Gastric ulcer – benign
- Polyps (a tumour that is usually noncancerous and grows on the mucus membrane)
- Pyloric stenosis (narrowing)
Abnormal results in the small intestine may indicate the following problems:
- Malabsorption syndrome
- Swelling and irritation (inflammation) of the small intestines
The test may also be done for the following conditions:
- Annular pancreas
- Duodenal ulcer
- Gastroesophageal reflux disease
- Intestinal obstruction
- Lower esophageal ring
- Primary or idiopathic intestinal pseudo-obstruction
You are exposed to a low level of radiation during this test, which carries a very small risk for 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 for x-rays.
Barium may cause constipation. Talk to your provider if the barium has not passed through your system by two or three days after the exam.
The upper GI series should be done after other x-ray procedures. This is because the barium that remains in the body may block details in other imaging tests.
Caroline DF, Dass C, Agosto O. The stomach. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison’s Diagnostic Radiology: A Textbook of Medical Imaging. 6th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2015:chap 27.
Kim DH, Pickhardt PJ. Diagnostic imaging procedures in gastroenterology. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 133.