A gastric emptying scan is also known as a gastric emptying study or test. This procedure uses nuclear medicine to determine how quickly food leaves the stomach. It’s different from a standard X-ray because it uses a small amount of radioactive material to emit photon energy. The energy is detected by a gamma camera, which creates a computerized image.
Gastric emptying scans are often used to diagnose gastroparesis, a condition in which the stomach's muscles don't work properly. This delays food from being sent to the small intestine.
Your doctor may order the scans if you frequently vomit, feel bloated after eating, or complain of abdominal pain. Other common symptoms of gastroparesis include:
- weight loss
- changes in blood sugar levels
- serious dehydration
- esophagitis, or inflammation of the esophagus
- malnutrition from not absorbing nutrients
Many of these symptoms can interfere with your quality of life. A gastric emptying scan can help your doctor diagnose gastroparesis or other motility disorder causing these symptoms.
Gastric emptying scans are performed at hospitals by professionals trained in nuclear medicine or radiology.
Before the scan, you’ll eat something solid (usually scrambled eggs), something liquid, and a small amount of tasteless radioactive material. The radioactive substance allows the camera to follow the food through the digestive process.
Then you will lie on a table while the camera takes pictures. Over the course of three to five hours, the camera will take four to six scans lasting about a minute each. Some hospitals use a gamma camera that takes pictures while you’re standing. In either case, it’s important to remain still during the scan.
Gastroparesis symptoms in children are similar to those seen in adults. Ask your doctor to administer this test to your child if they’re experiencing any of symptoms mentioned earlier.
The test for older children is identical to the test given to adults. If your child is a baby or infant, your doctor gives your child the radioactive food in milk or formula in an exam known as a milk study or liquid study. In this case, you may be instructed to bring your own formula or milk from home to make sure your child doesn't have an allergic reaction.
The radioactive substance is just as safe for your child as it is for an adult. The test usually takes about three hours for children. If your child is given the liquid study instead, the camera takes continuous images for about an hour. It’s important that your child remains still throughout the test. Make sure that you find a way to keep them occupied or calm before and during the test so that the results can be delivered smoothly. The following items may help keep your child relaxed:
- comfort objects, such blankets or pillows
You experience a small amount of radiation exposure from the material in the food you eat before your scan. This isn’t considered dangerous unless you’re breast-feeding, pregnant, or planning to become pregnant. Anyone in these circumstances should tell her doctor before having a gastric emptying scan.
Other than the radioactive meal before the scan, you shouldn’t eat or drink anything for four to six hours before the test. If you have diabetes, bring your medications or insulin in case your doctor requests that you take them with the test.
It's a good idea to bring books or music to pass the time. A parent might want to bring their child's favorite toy or pacifier.
Let the technician know if you are taking any medications. The following medications can all affect how quickly your stomach empties:
- prokinetic agents that speed up your digestive tract
- antispasmodic agents that slow down your digestive tract
- opioids, such as codeine, Norco, Percocet, and OxyContin
Health complications, such as diabetes or hypoglycemia, can affect the usefulness of the test. Your hormones can also affect your test results, so let your doctor if you’re in the second half of your menstruation cycle.
Your doctor may also use other tests to diagnose gastroparesis, including:
- a breath test, in which you eat a meal prepared with a specific type of carbon and give breath samples every few hours so that your doctor can analyze its contents
- the SmartPill, an electronic capsule that you swallow, which travels through your digestive tract and sends data to a data receiver that you keep with you throughout the test
- an ultrasound, which can allow your doctor to view your digestive tract and decide whether something other than gastroparesis is causing your symptoms
- an upper gastrointestinal (GI) endoscopy, in which your doctor uses an endoscope to view your esophagus, stomach, and the beginning of your small intestine to check for gastroparesis or blockage
- an upper GI series, in which you drink barium (which is easy to spot on an X-ray) and have a series of X-rays taken of your small intestine
Talk to your doctor about these alternatives if you have concerns about the gastric emptying test.
The doctor who ordered the test usually calls within a few days with results.
Your doctor may recommend medications such as metoclopramide (Reglan), erythromycin, or antiemetics to treat your gastroparesis and its symptoms. They may also suggest gastric electrical stimulation. In this procedure, a small device called a gastric neurostimulator is surgically inserted into your abdomen to stimulate the stomach muscles. This is usually recommended only if you don’t respond to medications.
In rare, serious cases, you may need a jejunostomy. In this procedure, your doctor inserts a feeding tube through your abdomen into the jejunum, a part of your small intestine. This procedure is only done if your gastroparesis is serious and has an enormous impact on your quality of life.
In most cases, diagnosing and treating gastroparesis before any major symptoms occur leads to a positive outcome.