1. What is Helicobacter Pylori Antigen Detection by Stool?

This is a non-invasive test used to detect the presence of Helicobacter pylori (H. pylori) antigens in a stool sample. It identifies current/active infection by detecting H. pylori proteins shed in the feces.

2. Why is this test done?

This test is recommended for:

• Diagnosing active H. pylori infection, especially in patients with dyspepsia or ulcers.
• Confirming eradication after antibiotic treatment (4 weeks post-therapy).
• When endoscopy is not feasible or needed (children, elderly, or low-resource settings).
• Screening in patients with gastric symptoms (e.g., bloating, nausea, upper abdominal pain, early satiety).

3. Normal Range

• Negative / Non-reactive: No H. pylori antigens detected in stool.
• Positive / Reactive: H. pylori antigen detected, suggesting active infection.

Exact numerical cut-offs vary by the method and manufacturer (e.g., ELISA-based or immunochromatography-based kits), but the result is typically qualitative (Positive or Negative).

4. Overview & Interpretation of Results

5. Associated Organs

• Stomach (primarily affects gastric mucosa)
• Duodenum

6. Associated Conditions

• Chronic gastritis
• Peptic ulcer disease (gastric/duodenal ulcers)
• Non-ulcer dyspepsia
• Gastric carcinoma (long-term infection risk)
• MALT lymphoma (rare lymphoid tumor)

7. Related / Follow-up Tests

• Urea Breath Test (UBT) – another non-invasive gold standard for active infection
• H. pylori IgG / IgM / IgA – serology (less preferred for current infection)
• Endoscopy + gastric biopsy – for histology, rapid urease test, or culture
• CBC – if ulcers are suspected (look for anemia)
• Fecal occult blood test (FOBT) – to check for gastrointestinal bleeding

8. Fasting Required?

• No fasting required.
• However, it is recommended to avoid antibiotics, PPIs, and bismuth for:
  • 2 weeks before testing (to reduce false negatives)

9. Summary Table

✅ Clinical Summary

The Stool Antigen Test for H. pylori is:

• Highly sensitive and specific (especially ELISA-based kits)
• Useful for both diagnosis and post-treatment confirmation
• A preferred choice in children and when endoscopy is to be avoided