Upper GI tests use X-rays to examine the esophagus, stomach, and first part of the small intestine (the duodenum). For these tests, a patient is asked to drink barium (a metallic liquid). As the barium passes through the digestive tract, it coats the esophagus, stomach, and first part of the small intestine so that a doctor can see them on the X-ray. Then a fluoroscope machine is held over the part of the body being examined, and the machine transmits images to a video monitor. 

The upper GI test is used to diagnose:

• Hiatal hernias
• Ulcers
• Tumors
• Esophageal varices
• Obstruction or narrowing of the upper GI tract

It may also be used to determine the causes of:

• Swallowing problems
• Reflux symptoms (dyspepsia or heartburn)
• Abdominal pain
• Diarrhea
• Unexplained vomiting, weight loss or bleeding