What tests may be used to diagnose common causes of dyspepsia?
PUD is commonly evaluated with upper endoscopy. If an endoscopy is performed, identification of Hp can be obtained via biopsies and visualization under a microscope. In addition to endoscopy, Hp can be diagnosed with breath, stool, or blood testing. Hp breath testing is based upon the fact that these organisms break down urea, a metabolic by-product, into carbon dioxide and ammonia. Patients consuming a radiolabeled urea excrete elevated levels of carbon dioxide, which can be quantified and used to detect the presence of the organism. Stool antigen testing is also available and both of these tests have high sensitivity and specificity. Blood tests to detect the presence of Hp are much less accurate and are best utilized for their ability to rule out Hp infection in low risk populations. They should not be used to assess confirmation of Hp eradication subsequent to treatment.