Helicobacter Pylori Stool Antigen Testing
Yes, there is a stool antigen test for H. pylori infection, which is one of the recommended non-invasive diagnostic methods with high sensitivity and specificity. 1
Diagnostic Methods for H. pylori
The American Gastroenterological Association recommends two primary non-invasive tests for initial diagnosis of H. pylori infection:
- Urea Breath Test (UBT) - Considered the gold standard non-invasive test
- Stool Antigen Test - An excellent alternative with comparable accuracy 1
Stool Antigen Test Details
The stool antigen test detects H. pylori antigens in fecal samples using enzyme-linked immunosorbent assay (ELISA) technology. Key characteristics include:
Important Considerations for Stool Antigen Testing
- Medication interference: Must discontinue proton pump inhibitors (PPIs), bismuth compounds, and antibiotics for 2 weeks prior to testing to avoid false negatives 1
- Post-treatment evaluation: Can be used to confirm eradication 4-8 weeks after completing therapy 1
- Early prediction: May predict eradication success as early as 7 days after treatment completion 2
Comparison with Other Diagnostic Methods
| Test | Advantages | Limitations |
|---|---|---|
| Stool Antigen Test | Non-invasive, high accuracy, detects active infection | Requires medication discontinuation |
| Urea Breath Test | Non-invasive, gold standard, high accuracy | Requires specialized equipment, medication discontinuation |
| Serology (IgG) | No medication interference | Cannot distinguish active from past infection, not for eradication confirmation [1] |
| Endoscopic Tests | Direct visualization, allows biopsy | Invasive, costly, patient discomfort |
When to Use Stool Antigen Testing
The stool antigen test is particularly useful in:
- Initial diagnosis of suspected H. pylori infection
- Confirmation of eradication after treatment
- Pediatric patients where non-invasive testing is preferred
- Epidemiological studies 4
- Patients unable to undergo endoscopy
- Follow-up testing after treatment 1
Common Pitfalls to Avoid
- Using serology to confirm eradication (antibodies persist after treatment)
- Testing too soon after treatment completion
- Failing to stop PPIs, bismuth, or antibiotics before testing
- Not considering local antibiotic resistance patterns when selecting therapy 1
For patients with alarm symptoms (bleeding, weight loss, anemia), endoscopy with biopsy is recommended to rule out cancer rather than relying solely on non-invasive testing 1.