A physician may order follow-up tests to diagnose problems with the gastrointestinal (GI) system. Depending on symptoms, a physician may order one or more of the following tests of the upper GI tract:

• Manometry. A manometer (tube lined with pressure gauges) guided down the throat measures the contractions of the esophagus (esophageal manometry) and/or stomach (gastric manometry). It may be used in suspected cases of gastroparesis or other conditions involving the nerves or muscles of the upper digestive system.
  
  
• Endoscopy. The physician guides a fiber-optic viewing tube (endoscope) through the patient’s mouth to examine the esophagus or stomach for lesions, blockage or other problems.
  
  
• Ultrasound. A probe delivers harmless sound waves. An ultrasound creates pictures that outline the organs but does not detail the lining of the GI system.  An abdominal ultrasound can show excess formation of fluid or abnormal size or shape of an organ.
  
  
• Esophageal pH test. This test measures the acidity in the throat. It can indicate acid reflux, the abnormal presence of stomach acid in the esophagus.
  
  
• Bravo capsule pH monitoring system. This test allows physicians to measure the acidity in the throat 24 hours beyond the traditional and routinely used esophageal pH measuring sytem.
  
  
• Bernstein test (esophageal acid perfusion test). This test for esophagitis (inflammation of the esophagus) introduces a small quantity of acid in the esophagus through a nasogastric tube to reproduce symptoms of heartburn. However, this test is rarely performed due to the availability of more effective diagnostic tests.
  
  
• Gastric emptying scan (GES). The patient eats food containing a tracer (a radioisotope, with a low, safe level of radiation). The patient then lies down and a scanning machine is placed above the abdomen for several hours. The tracer allows the machine to track the radioactivity in the stomach and show how fast the food exits the organ. gastroparesis is suspected if the stomach retains more than half the food after two hours.
  
  
• 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 duodenum. 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.