Which test is considered the gold standard for diagnosing H. pylori?

• A. Urea breath test
• B. Stool antigen test
• C. EGD with biopsy (rapid urease test)
• D. Serology

Answer: (C)

Detecting active H. pylori infection relies on direct evidence of the organism in the stomach lining. When endoscopy is performed, a biopsy sample can be tested for urease activity. H. pylori produces urease, which breaks down urea to increase the local pH and triggers a rapid color change in a urease test medium. This rapid urease test on biopsy provides real-time, tissue-based confirmation of infection during the procedure, making it the best-established diagnostic standard in many clinical settings.

Noninvasive options like the urea breath test and stool antigen test are highly accurate for detecting active infection but don’t provide tissue confirmation and can be affected by recent antibiotic or proton pump inhibitor use. Serology detects antibodies and cannot distinguish current infection from past exposure, so it’s less reliable for confirming active infection or treatment success.