H. Pylori Stool Test: Name and Ordering Information
The test is called the "Stool Antigen Test" (SAT) and should be ordered specifically as a laboratory-based monoclonal antibody test, not a rapid in-office test. 1
Exact Test Name and Ordering Details
- Order as: "H. pylori Stool Antigen Test" using ELISA format with monoclonal antibodies 1
- Avoid: Rapid in-office immunochromatographic stool tests, which have significantly lower accuracy and should not be used 1, 2
- Laboratory requirement: Must be a validated laboratory-based test using monoclonal antibodies to ensure accuracy of approximately 93% sensitivity and 93% specificity 1, 2
Critical Pre-Test Requirements
Before ordering the stool test, ensure the patient meets these medication washout requirements to avoid false-negative results:
- Stop antibiotics and bismuth products: At least 4 weeks before testing 3, 2
- Stop proton pump inhibitors (PPIs): At least 2 weeks before testing (preferably 2 weeks) 1, 3
- Alternative during washout: Histamine-2 receptor antagonists can be substituted for PPIs as they do not affect bacterial load 1
When to Use Stool Antigen Test
- Initial diagnosis: Preferred non-invasive test for patients under 50 years without alarm symptoms 2
- Confirmation of eradication: Use at least 4 weeks after completing treatment (never use serology for this purpose) 3, 2
- Equivalent accuracy to urea breath test: Both detect active infection with comparable performance 1, 2
Common Ordering Pitfalls to Avoid
- Do not order serology tests - they cannot distinguish active infection from past exposure and have only 78% accuracy 2
- Do not use rapid office-based stool tests - these have limited accuracy compared to laboratory ELISA tests 1, 2
- Do not order if patient recently took PPIs or antibiotics - wait the appropriate washout period or results will be falsely negative 1, 3
- Do not use stool test to confirm eradication too early - must wait at least 4 weeks after treatment completion 3, 2