At Mayo Clinic, a comprehensive evaluation of stomach symptoms usually includes an analysis of your entire digestive tract as well as your nervous system. This approach helps determine whether your problem is confined to the stomach or involves other areas of the gastrointestinal tract. It also helps differentiate between problems caused by the nerves and those caused by muscles in the stomach. Mayo Clinic specialists often use advanced tests that may not be widely available, and are expert at analyzing complex diagnostic studies.
At Mayo Clinic, one of the first steps in evaluating stomach problems is upper endoscopy. This minimally invasive test uses a thin, flexible tube with a tiny camera at the tip to examine your stomach and small intestine. Rather than diagnosing gastroparesis, upper endoscopy rules out obstructions and other conditions that can slow stomach emptying.
A gastric emptying study, which uses a small amount of radioactive material to track how quickly food leaves your stomach, is generally considered the definitive test for gastroparesis. Motility disorders specialists at Mayo Clinic are leading proponents of a four-hour gastric emptying test, rather than the standard two-hour exam, which may not detect delayed emptying. Another study commonly used at Mayo Clinic is whole gut transit scintigraphy. This test measures stomach emptying as well as small intestine and colon transit in a single, noninvasive procedure.
Generally performed if your transit test is abnormal, gastroduodenal manometry measures how well the smooth muscles of your stomach and small intestine contract and relax. The test uses a pressure-sensitive plastic tube that is threaded down the throat and into the stomach and small intestine. The tube is connected to a computer that monitors the strength, frequency and coordination of muscle contractions before and after you eat.
For people found to have nerve dysfunction, the next step is usually an autonomic reflex screen, a panel of tests developed in conjunction with Mayo Clinic autonomic neurologists (physicians who specialize in the autonomic nervous system). These tests analyze a broad range of autonomic functions, including the movement of food through the digestive tract.
The autonomic reflex screen may be used in conjunction with a paraneoplastic panel. Available at only a few medical centers, this test checks a sample of your blood for antibodies associated with rare nervous system disorders that can cause severe stomach dysmotility.
Motility disorders specialists at Mayo Clinic have chosen not to use certain tests to diagnose gastroparesis at this time, though they may be adopted in the future. Among these tests are electrogastrography, which measures electrical signals in the stomach, and SmartPill, a device you swallow that helps identify problems with intestinal transit.