Helicobacter pylori test, how to interpret results?

Helicobacter tests: Rapid tests for h. pylori are based on it's fairly unique enzyme urease, producing ammonia. This can be detected in gas (breath test), or pH-based media testing of tissue samples. The best test is a biopsy, perhaps with direct detection by IHC. The latter method also can find other complications like cancer. Stool antigen tests are also available. Serologic tests only tell if you have ever had it.