Gastric Emptying Study

What is a gastric emptying study?

A gastric emptying study is a procedure done by nuclear medicine physicians that measures the emptying of food from the stomach.

When is a gastric emptying study used?

A gastric emptying study is used to diagnose abnormal emptying of food from the stomach. The study usually is done when a patient has continued nausea and vomiting, signs that the stomach is not emptying normally. One of the most common diseases in which there may be abnormal emptying of food from the stomach is diabetes mellitus.

How is a gastric emptying study done?

For a gastric emptying study, a patient eats a meal in which the solid food, liquid food, or both, are mixed with a small amount of radioactive material. A scanner (acting like a Geiger counter) is placed over the stomach to monitor the amount of radioactivity in the stomach for several hours after the test meal.

How are the results of a gastric emptying study evaluated?

In patients with gastroparesis (a disease which involves paralysis of the stomach muscles and nerves), the food and radioactive material remain in the stomach longer than normal (usually hours) before emptying into the small intestine. As a result, the scanner continues to show radioactivity in the area of the stomach for hours after the test meal. If abnormally slow emptying is demonstrated, medications such as cisapride (PROPULSID) or metoclopramide (REGLAN) may be given to speed up the emptying.

Are there any side effects of a gastric emptying study?

There are no side-effects of a gastric emptying study. The radioactive material is not absorbed into the body and is eliminated in the stool. Nevertheless, gastric emptying studies—and any other studies that utilize radioactive materials—should not be performed in pregnant women because the fetus is exposed to some radioactivity.

Are there other tests that can be performed instead of a gastric emptying study?

An upper gastrointestinal x-ray series demonstrates abnormal emptying of barium in patients with severe emptying problems. However, this test cannot diagnose abnormal emptying of a mild or moderate degree. An antro-duodenal motility study or an electrogastrogram can demonstrate abnormalities in the muscles and nerves of the stomach, but they do not directly evaluate the effects of these abnormalities on the emptying process of the stomach. Other experimental methods for evaluating emptying of the stomach have been described, for example, ultrasonography, but are available in very few centers and have not been well-studied.