Gastroparesis is a kind of paralysis of the stomach and is most often due to a damaged vagus nerve. The vagus nerve is responsible for many functions, including peristalsis, which is the process of smooth muscle contractions that help to move the food you eat from your stomach to your duodenum. Gastroparesis may be a temporary condition which comes as a response to an acute illness or a specific medication, and may resolve when you stop taking that medication or when you recover from your ailment. In the case where gastroparesis is a chronic ailment, this is most often due to autonomic neuropathy.
Chronic gastroparesis can occur in people with either type 1 or type 2 diabetes. The high levels of blood glucose, sustained over a number of years sometimes results in permanent damage to the vagus nerve. Gastroparesis has also been found to occur in those who suffer from various autoimmune diseases, such as fibromyalgia and Parkinson's disease, or may be seen in those people who have mitochondrial disorder. Sometimes there are other causes for a damaged vagus nerve and subsequent chronic gastroparesis, including abdominal surgery.
If your doctor thinks you may have gastroparesis, he may order tests to either diagnose the condition or rule out other conditions which cause similar symptoms. The standard diagnostic tests include the following:
Gastric emptying studies-Most doctors agree that this is the most accurate means of diagnosing gastroparesis. In the most common gastric emptying test, you'll be given eggs or oatmeal containing a small quantity of radioactive material. A scanning device is placed over your stomach to measure how fast the food leaves your stomach. There are other tests that can measure the tension in your stomach muscles after food is eaten. If the muscles don't relax as they should, there may be symptoms that mimic the delayed stomach emptying that is found with gastroparesis.
Gastroduodenal manometry-A thin plastic tube is led from your throat down into the stomach and small intestine. The tube is sensitive to and can measure pressure. This tube is hooked up to a computer that can tell your doctor about the peristaltic waves of your stomach: whether they are fast enough, strong enough, and are well-coordinated with meal times. While this test is useful for distinguishing between the various stomach conditions related to motility, the test isn't available at every facility, and isn't often needed to make a diagnosis of gastroparesis.
Upper gastrointestinal endoscopy or Upper GI-This test is performed to rule out conditions other than gastroparesis which might cause delayed gastric emptying. In this test, a tube containing a miniature camera is swallowed and this allows the doctor to see any blockages of the stomach and small intestine.
Electrogastrogram-This procedure is still in its experimental stages and is similar to the electrocardiogram in that it measures electrical signals in a specific part of the body. The electrogastrogram measures the electrical signals in your stomach prior to and after meals. In a healthy stomach, these signals are regular and speed up after a meal is consumed, but in those with gastroparesis, the speed is irregular and doesn't get faster after food is eaten, or may not be apparent at all.
Magnetic resonance imaging (MRI)-MRI employs a strong magnet and radio waves to make cross-sectional images of your body. MRI is used to diagnose many conditions and its advantages are that it's not invasive and there's no radiation involved in the procedure.