Content Map Terms
An upper GI series looks at the upper and middle sections of the gastrointestinal tract. The test uses barium contrast material, fluoroscopy, and X-ray.
Before the test, you drink a mix of barium (barium contrast material) and water. The barium is often combined with gas-making crystals. Your doctor watches the barium move through your esophagus, stomach, and the first part of the small intestine (duodenum) on a video screen. Several X-ray pictures are taken at different times and from different views.
A small bowel follow-through may be done right away after this test to look at the rest of the small intestine. If just the throat and esophagus are looked at, it's called an esophagram (or barium swallow).
Upper endoscopy is done instead of an upper GI series in certain cases. Endoscopy uses a thin, flexible tube (endoscope) to look at the lining of the esophagus, stomach, and upper small intestine (duodenum).
Why It Is Done
An upper GI series is done to:
- Find the cause of gastrointestinal symptoms, such as trouble swallowing, vomiting, burping up food, belly pain (including a burning or gnawing pain in the centre of the stomach), or indigestion.
- Find narrow spots (strictures) in the upper intestinal tract, ulcers, tumours, polyps, or pyloric stenosis.
- Find inflamed areas of the intestine, malabsorption syndrome, or problems with the squeezing motion that moves food through the intestines (motility disorders).
- Find swallowed objects.
Generally, an upper GI series is not used if you do not have symptoms of a gastrointestinal problem. An upper GI series is done most often for people who have:
- A hard time swallowing.
- A possible blocked intestine (obstruction).
- Belly pain that is relieved or gets worse while eating.
- Severe heartburn or heartburn that occurs often.
How To Prepare
You may be asked to eat a low-fibre diet for 2 or 3 days before the test. You may also be asked to stop eating for 12 hours before the test. Your doctor will tell you if you need to stop taking certain medicines before the test.
The evening before the test, you may be asked to take a laxative to help clean out your intestines. If your stomach can't empty well on its own, you may have a special tube put through your nose and down into your stomach just before the test begins. A gentle suction on the tube will drain the stomach contents.
If you are having the small bowel follow-through after the upper GI series, you'll need to wait between X-rays. The entire small bowel follow-through examination takes up to 6 hours, so bring along a book to read or some other quiet activity.
How It Is Done
An upper GI series is usually done in a clinic or the X-ray department of a hospital. You don't need to stay overnight in the hospital.
Before the test
You will need to take off your clothes and put on a hospital gown. You will need to take out any dentures and take off any jewellery. You may not smoke or chew gum during the test, since the stomach will respond by making more gastric juices. This will slow the movement of the barium through the intestines.
You will lie on your back on an X-ray table. The table is tilted to bring you to an upright position with the X-ray machine in front of you. Straps may be used to keep you safely on the table. The technologist will make sure you are comfortable during changes in table position.
During the test
You will have one X-ray taken before you drink the barium mix. Then you will take small swallows repeatedly during the series of X-rays that follow. The radiologist will tell you when and how much to drink. By the end of the test, you may have swallowed 250 mL (1 cup) to 750 mL (3 cups) of the barium mixture.
The radiologist watches the barium pass through your gastrointestinal tract using fluoroscopy and X-ray pictures. The table is tilted at different positions and you may change positions to help spread the barium. Some gentle pressure is put on your belly with a belt or by the technologist's gloved hand. You may be asked to cough so that the radiologist can see how that changes the barium flow.
If you are having an air-contrast study, you will sip the barium liquid through a straw with a hole in it or take pills that make gas in your stomach. The air or gas that you take in helps show the lining of the stomach and intestines in greater detail.
If you are also having a small bowel study, the radiologist watches as the barium passes through your small intestine into your large intestine. X-ray pictures are taken every 30 minutes.
After the test
You may be given a laxative or enema to flush the barium out of your intestines after the test to prevent constipation.
How long the test takes
The test will take about 30 to 40 minutes. If you are also having a small bowel study, the test will take 2 to 6 hours.
How It Feels
The barium liquid is thick and chalky. Some people find it hard to swallow. A sweet flavour, like chocolate or strawberry, is used to make it easier to drink. Some people don't like it when the X-ray table tilts. You may find that pressure on your belly is uncomfortable. After the test, many people feel bloated and a little nauseated.
Barium doesn't move into the blood, so allergic reactions are very rare.
Some people gag while drinking the barium fluid. In rare cases, a person may choke and inhale (aspirate) some of the liquid into the lungs.
There is a small chance that the barium will block the intestine or leak into the belly through a perforated ulcer. A special type of contrast material (Gastrografin) can be used if you have a blockage or an ulcer.
There is always a small chance of damage to cells or tissue from being exposed to any radiation, even the low level of radiation used for this test.
Results are usually ready in 1 to 3 days.
The esophagus, stomach, and small intestine all look normal.
A narrowing (stricture), inflammation, a mass, a hiatal hernia, or enlarged veins (varices) may be seen. Spasms of the esophagus or a backward flow (reflux) of barium from the stomach may occur.
The upper GI series may show a stomach (gastric) or intestinal (duodenal) ulcer, a tumour, or something pushing on the intestines from outside the gastrointestinal tract. Narrowing of the opening between the stomach and the small intestine (pyloric stenosis) may be seen.
The small bowel follow-through may show inflammation or changes in the lining that may explain poor absorption of food. This may be caused by Crohn's disease or celiac disease.
Current as of:
June 17, 2021
Author: Healthwise Staff
E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine
Martin J. Gabica MD - Family Medicine
Jerome B. Simon MD, FRCPC, FACP - Gastroenterology
Current as of: June 17, 2021
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Martin J. Gabica MD - Family Medicine & Jerome B. Simon MD, FRCPC, FACP - Gastroenterology
Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
HealthLinkBC Files are easy-to-understand fact sheets on a range of public health and safety topics including disease prevention and immunizations.
Browse Disease Prevention HealthLinkBC Files
Find Services and Resources
If you are looking for health services in your community, you can use the HealthLinkBC Directory to find hospitals, clinics, and other resources.