This is a medical question of type : exams and tests 
 How to diagnose Gastroparesis ? 
 Gastroparesis is diagnosed through a physical exam, medical history, blood tests, tests to rule out blockage or structural problems in the GI tract, and gastric emptying tests. Tests may also identify a nutritional disorder or underlying disease. To rule out any blockage or other structural problems, the health care provider may perform one or more of the following tests:
                
- Upper gastrointestinal (GI) endoscopy. This procedure involves using an endoscopea small, flexible tube with a lightto see the upper GI tract, which includes the esophagus, stomach, and duodenumthe first part of the small intestine. The test is performed at a hospital or outpatient center by a gastroenterologista doctor who specializes in digestive diseases. The endoscope is carefully fed down the esophagus and into the stomach and duodenum. A small camera mounted on the endoscope transmits a video image to a monitor, allowing close examination of the intestinal lining. A person may receive a liquid anesthetic that is gargled or sprayed on the back of the throat. An intravenous (IV) needle is placed in a vein in the arm if general anesthesia is given. The test may show blockage or large bezoarssolid collections of food, mucus, vegetable fiber, hair, or other material that cannot be digested in the stomachthat are sometimes softened, dissolved, or broken up during an upper GI endoscopy.  - Upper GI series. An upper GI series may be done to look at the small intestine. The test is performed at a hospital or outpatient center by an x-ray technician, and the images are interpreted by a radiologista doctor who specializes in medical imaging. Anesthesia is not needed. No eating or drinking is allowed for 8 hours before the procedure, if possible. If the person has diabetes, a health care provider may give different instructions about fasting before the test. During the procedure, the person will stand or sit in front of an x-ray machine and drink barium, a chalky liquid. Barium coats the small intestine, making signs of gastroparesis show up more clearly on x rays. Gastroparesis is likely if the x ray shows food in the stomach after fasting. A person may experience bloating and nausea for a short time after the test. For several days afterward, barium liquid in the GI tract causes stools to be white or light colored. A health care provider will give the person specific instructions about eating and drinking after the test.  - Ultrasound. Ultrasound uses a device, called a transducer, that bounces safe, painless sound waves off organs to create an image of their structure. The procedure is performed in a health care providers office, outpatient center, or hospital by a specially trained technician, and the images are interpreted by a radiologist; anesthesia is not needed. The images can show whether gallbladder disease and pancreatitis could be the cause of a persons digestive symptoms, rather than gastroparesis.  - Gastric emptying scintigraphy. The test involves eating a bland mealsuch as eggs or an egg substitutethat contains a small amount of radioactive material. The test is performed in a radiology center or hospital by a specially trained technician and interpreted by a radiologist; anesthesia is not needed. An external camera scans the abdomen to show where the radioactive material is located. The radiologist is then able to measure the rate of gastric emptying at 1, 2, 3, and 4 hours after the meal. If more than 10 percent of the meal is still in the stomach at 4 hours, the diagnosis of gastroparesis is confirmed.  - SmartPill. The SmartPill is a small electronic device in capsule form. The SmartPill test is available at specialized outpatient centers. The images are interpreted by a radiologist. The device is swallowed and moves through the entire digestive tract, sending information to a cell-phone-sized receiver worn around the persons waist or neck. The recorded information provides a detailed record of how quickly food travels through each part of the digestive tract.  - Gastric emptying breath test. With this test, the person eats a special test meal that includes a natural material with a special type of carbon in it. Then, breath samples are taken over a period of several hours to measure the amount of the material in the exhaled breath. The results allow the health care provider to calculate how fast the stomach is emptying.