Gastric emptying tests are tests that measure the time it takes for food to empty out of your stomach. After a meal, it normally takes 1 1/2 to two hours for food to move out of the stomach and into the small intestine. When your stomach takes longer than normal to empty, it’s called gastroparesis.
If food stays in your stomach for too long, it can harden into a solid mass called a bezoar. A bezoar may lead to a dangerous blockage that prevents food from passing into your small intestine.
Gastroparesis may also cause malnutrition (not getting enough nutrients from your food).
Gastric emptying tests may help you get treatment for gastroparesis before it causes serious complications.
Other names: gastric emptying study, gastric emptying scan, gastric emptying scintigraphy, smart pill, wireless motility study, gastric emptying breath test, upper GI series, barium swallow
What are they used for?
Gastric emptying tests are most often used to diagnose gastroparesis.
Why do I need a gastric emptying test?
You may need this test if you have symptoms of gastroparesis, which include:
- Abdominal pain
- Nausea and vomiting
- A feeling of fullness after just a few bites of food
- Loss of appetite
- Weight loss
What happens during a gastric emptying test?
Gastric emptying tests are most often done by a radiologist or radiology technician. A radiologist is a doctor who specializes in using imaging tests to diagnose and treat diseases and injuries. There are different types of tests. You may have one or more of the following tests:
Gastric emptying study, also known as a gastric emptying scan, or gastric emptying scintigraphy. This is the most common test used to diagnose gastroparesis. During this test:
- You will start by eating a light meal, often eggs and toast. The food will contain a small, harmless amount of radioactive material called a tracer.
- After you finish eating, you will lie down on an x-ray table.
- The radiologist will take images of your abdomen, using a scanning device.
- The radiologist will watch the movements of the radioactive tracer on a monitor. The tracer will show how food travels through your stomach.
- Additional images will be taken over the next few hours to see how long it takes for food to move out of your stomach and into your gastrointestinal tract.
- You will be allowed to get up and leave the exam room during this time period. Your provider will let you know when you need to return for imaging. It’s usually at around 1, 2, and 4 hours after the first image was taken.
A gastric emptying study may also be done using a liquid that contains the radioactive tracer, instead of solid food.
Upper GI series, also known as a barium swallow. During this test:
- You will swallow a drink that contains barium. Barium is a substance that makes parts of your body show up more clearly on an x-ray.
- You will lie on an x-ray table.
- A special type of x-ray called a fluoroscopy will track the barium in real time as it moves through your esophagus, stomach, and small intestine.
- You may be asked to change positions while more images are taken.
Gastric emptying breath test. During this test:
- You will eat a meal or drink a liquid that contains a type of protein that your body absorbs. The substance eventually passes into your breath.
- A provider will collect samples of your breath over a period of about four hours.
- You may be able to leave the exam room during this time period but will need to sit quietly. You should not smoke or eat while you wait. Your provider will let you know when you need to return for imaging.
- The amount of the substance found in your breath samples can help show how fast the stomach has emptied.
Smart pill, also known as a wireless motility capsule. During this test:
- You will swallow a smart pill, which is a small electronic device.
- You will then proceed with your normal daily activities.
- As you go through your day, the smart pill will travel through your gastrointestinal system and collect data.
- The data is sent to a receiver that you wear, usually around your waist.
- After a day or two, the smart pill will leave your body in a bowel movement.
- You may not feel it when it exits your body. So when you have bowel movement, wait 3 minutes before flushing This will ensure the receiver captures the data, even after the capsule leaves your body.
- After 4 or 5 days, you will return the receiver to the radiologist who will review the results.
Will I need to do anything to prepare for the test?
You may need to fast (not eat or drink) for several hours before your test. Your provider will also let you know if you need to stop taking certain medicines before your test.
Are there any risks to the test?
You should not have a gastric emptying study or an upper GI series if you are pregnant or think you may be pregnant. Radiation from these imaging tests can be harmful to an unborn baby. For others, there is little risk to having an imaging test. The dose of radiation is very low and not considered harmful for most people. But talk to your provider about all the x-rays you’ve had in the past. The risks from radiation exposure may be linked to the number of x-ray treatments you’ve had over time.
There is very little risk to having a gastric breath test or taking a smart pill. In rare cases, a smart pill may get stuck in the digestive system. If the pill takes longer than several days to leave your body in a bowel movement, contact your health provider.
What do the results mean?
If your results show it took longer than normal for your stomach to empty, it probably means you have gastroparesis.
Is there anything else I need to know about gastric emptying tests?
Treatment for gastroparesis may involve taking certain medicines and/or treating the condition that is causing the problem, such as diabetes. Regardless of the cause, your provider will likely recommend that you make changes to your diet and eating habits. These may include:
- Eating foods low in fiber and fat.
- Avoiding carbonated drinks, smoking, and alcohol.
- Eating smaller meals throughout the day, rather than two or three large meals.
- Chewing food thoroughly.
- Waiting at least two hours after eating before lying down.