Gastric Emptying Tests

Why this test may be ordered

• To diagnose gastroparesis (delayed gastric emptying)
• To check for other problems with food passing through your stomach
• If you have symptoms such as abdominal pain, bloating, nausea, vomiting, feeling full after a few bites, loss of appetite, or weight loss

Preparation and collection

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.

There are several types of gastric emptying tests. The most common is a gastric emptying scan (scintigraphy): you eat a light meal containing a small amount of radioactive tracer, then lie on an x-ray table while images are taken over several hours to track the tracer. An upper GI series (barium swallow) involves swallowing a chalky liquid containing barium, and x-rays are taken as it moves through your digestive tract. A gastric emptying breath test requires you to eat a meal or drink a liquid containing a special protein; breath samples are collected over about four hours. A smart pill (wireless motility capsule) is a pill-sized device you swallow; it travels through your gastrointestinal system and sends data to a receiver you wear; it passes in your bowel movement after a day or two.

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 a developing 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. If you're having an upper GI series, tell your provider if you have any known allergies to the barium used in the test. Also, your poop may look white for several days after the test as you pass the barium. You may have constipation if all the barium doesn't pass out of your body. 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 your digestive system. If the pill takes longer than several days to leave your body in a bowel movement, contact your provider.

Understanding results

Your healthcare provider will interpret your results based on the time it takes for your stomach to empty. Results are compared to normal emptying times, which typically take about four hours for 90% of food to leave the stomach. Ask your provider for the specific reference range.

• Longer than normal: Gastroparesis Limitation: Longer than normal emptying time Next step: If your results show it took a longer-than-normal time for your stomach to empty, it could mean you have gastroparesis (delayed gastric emptying).
• Shorter than normal: Dumping syndrome Limitation: Shorter than normal emptying time Next step: If your results show it took a shorter-than-normal time for your stomach to empty, it could mean you have dumping syndrome (rapid gastric emptying).

• For imaging tests (gastric emptying scan and upper GI series): there is a small amount of radiation exposure, which is very low and not considered harmful for most people, but these tests should not be performed if you are pregnant or think you may be pregnant.
• For the upper GI series, there is a risk of allergy to barium and possible constipation if the barium does not pass completely.
• For the gastric emptying breath test and smart pill, there is very little risk.
• In rare cases, a smart pill may get stuck in your digestive system; contact your provider if it takes longer than several days to pass.

What to do next

If you are diagnosed with gastroparesis, treatment may involve medicines and/or treating the underlying condition (such as diabetes). Your provider will likely recommend dietary changes: eating low-fiber, low-fat foods; avoiding carbonated drinks, smoking, and alcohol; eating smaller meals more frequently; chewing food thoroughly; and waiting at least two hours after eating before lying down.

• Do you have symptoms such as abdominal pain, bloating, nausea, vomiting, feeling full after a few bites, loss of appetite, or weight loss?
• Do you have diabetes or other conditions that may affect stomach emptying?
• Are you pregnant or think you may be pregnant?

Evidence source

U.S. National Library of Medicine: Gastric Emptying Tests