Diagnosis

Although your doctor is likely to suspect gastritis after talking to you about your medical history and performing an exam, you may also have one or more of the following tests to pinpoint the exact cause.

• Tests for H. pylori. Your doctor may recommend tests to determine whether you have the bacterium H. pylori. Which type of test you undergo depends on your situation. H. pylori may be detected in a blood test, in a stool test or by a breath test.

  For the breath test, you drink a small glass of clear, tasteless liquid that contains radioactive carbon. H. pylori bacteria break down the test liquid in your stomach. Later, you blow into a bag, which is then sealed. If you're infected with H. pylori, your breath sample will contain the radioactive carbon.

• Using a scope to examine your upper digestive system (endoscopy). During endoscopy, your doctor passes a flexible tube equipped with a lens (endoscope) down your throat and into your esophagus, stomach and small intestine. Using the endoscope, your doctor looks for signs of inflammation.

  If a suspicious area is found, your doctor may remove small tissue samples (biopsy) for laboratory examination. A biopsy can also identify the presence of H. pylori in your stomach lining.

• X-ray of your upper digestive system. Sometimes called a barium swallow or upper gastrointestinal series, this series of X-rays creates images of your esophagus, stomach and small intestine to look for abnormalities. To make the ulcer more visible, you may swallow a white, metallic liquid (containing barium) that coats your digestive tract.