What is the H. pylori breath test? The H. pylori breath test is a simple and safe test used to detect an active H. pylori infection. What is H. pylori? Helicobacter pylori (abbreviated as H. pylori) is a bacteria that can infect the stomach or duodenum (first part of the small intestine). If left untreated, H. pylori bacteria can cause gastritis (an inflammation or irritation of the stomach lining) and duodenal or gastric ulcers. In addition, infection with H. pylori increases the risk of other diseases and is also a risk factor for gastric cancer. Accurate detection of H. pylori is the first step toward curing stomach and intestinal ulcers, and preventing the development of more serious gastrointestinal problems What happens during the test? During the test, you will be asked to exhale into a balloon-like bag. The air you breathe into this bag is tested to provide a basis for comparison (called a baseline sample). You will then be asked to drink a small amount of a pleasant lemon-flavored solution. Fifteen minutes after drinking the solution, a second breath sample will be taken. The air you breathe into this bag is tested for an increase in carbon dioxide.