What Is H. pylori Antigen?
What it is
H. pylori antigen in stool is a direct marker of active Helicobacter pylori colonization of the stomach.
Why it matters
Stool antigen detects active infection and is suitable for post-treatment (test-of-cure) confirmation.
Specimen
Stool
Interpretation
Positive = H. pylori antigen detected (active infection). Negative = not detected.
Limitations
Recent PPI/antibiotic use can cause false negatives; suitable for test-of-cure.
Related test: H. pylori Antigen Rapid Test — specimen: Feces
Frequently Asked Questions
Can a stool antigen test confirm cure? Yes — it detects active infection and is suitable for test-of-cure after eradication.
Related knowledge
References
- Malfertheiner P et al. Management of Helicobacter pylori infection: Maastricht VI/Florence consensus report. Gut. 2022.
Last reviewed: 2026-09-12