Gastroparesis is usually diagnosed by a physician during a physical examination that includes the patient’s medical history.

There a number of tests that a physician may perform to diagnose gastroparesis. They include:

• Blood tests. These check levels of substances in the blood, including glucose (blood sugar). Erratic glucose blood levels is one possible sign of gastroparesis. Blood tests can indicate malnutrition in extreme cases of gastroparesis.
  
  
• Gastric emptying study. Test that measures the rate at which contents exit the stomach. The test is widely available and often considered the best way to determine whether a patient has gastroparesis. During the test, a patient eats solid food (usually eggs or oatmeal) that contains a tiny amount of radioactive material. After eating, the patient lies underneath a machine that takes pictures of the food as it passes through the stomach.
  
  
• Upper GI barium test. Allows physicians to analyze pictures of the patient’s stomach. After fasting for at least 12 hours, the patient ingests barium (a white liquid that shows up on x-rays) before x-rays are taken. The stomach is normally empty after a 12-hour fast. Therefore, if food remains in the stomach, it may indicate gastroparesis.
  
  
• Barium beefsteak meal. Test that allows physicians to observe the stomach during a meal. Patients ingest food that contains barium and the stomach is observed through x-rays, which allows the physician to determine how well the stomach is functioning. This test may detect problems that do not appear during the upper GI barium test.
  
  
• Antroduodenal motility study. The patient is sedated or has the throat numbed. A tube is passed down the throat and through the stomach into the upper part of the small intestine. Sensors in the tube measure the contractions of the digestive tract at rest and after a meal and reveal whether emptying of the stomach is delayed. The test evaluates the contraction ability of the stomach and duodenum muscles.
  
  
• Gastroduodenal manometry. Test that measures the strength, frequency and coordination of muscle contractions in the stomach and small intestine while eating. It is conducted by inserting a tube (manometry catheter) through the esophagus into the stomach to the small intestine. Muscle contractions are recorded before and after the patient eats. This test is not widely available and may not be necessary for diagnosing gastroparesis.
  

To help rule out conditions other than gastroparesis that may be producing symptoms, a physician may perform the following tests:

• Upper endoscopy. Test that allows the physician to inspect the stomach for abnormalities. A thin tube with a tiny camera (endoscope) is inserted into the mouth and passed through the esophagus into the small intestine. This test, which is usually performed with a sedative, can detect conditions that may be causing gastric emptying problems, such as cancer or hernias.
  
  

  

• Small intestinal x-ray. Test in which pictures of the small intestine are taken. This can detect blockages which may be causing gastric emptying problems.
  
  
• Ultrasound. Test that uses sound waves to produce images of the shape and outline of various tissues and organs in the body. This test can help a physician detect other problems that may be causing symptoms, such as gallbladder disease or pancreatitis.