HELICOBACTER PYLORI ANTIGEN, STOOL

Helicobacter pylori is a bacterium that lives in the stomach lining and is one of the commonest causes of gastritis, acidity that keeps returning, and stomach or duodenal ulcers. The stool antigen test detects pieces of the bacterium in a stool sample — proof of a current, active infection.

Unlike a blood antibody test, which can stay positive for years after the infection has cleared, the stool antigen test reflects what is present now. That is why doctors also use it after treatment, to confirm the infection has actually been eradicated.

When do doctors advise this test?

• Acidity, burning or upper-abdominal pain that keeps coming back
• Diagnosed gastritis or a stomach/duodenal ulcer
• Long-standing indigestion, bloating or burping under evaluation
• After completing H. pylori treatment, to confirm eradication (usually a few weeks later, as advised)

Preparation & the sample

A fresh stool sample is needed — the team will guide you on the container and quantity. Some medicines can cause a false negative: antibiotics and bismuth in the previous four weeks, and acidity-suppressing PPIs in the previous two weeks, commonly interfere. Do not stop any medicine on your own — ask your doctor how to time the test.

This information is educational and general. Your doctor's advice for your specific situation always comes first.