General Antigen (Fecal) - Fecal Occult Blood Detection (Immunochemical)
This test checks for hidden blood in your stool, which may signal early signs of colorectal cancer or other gastrointestinal bleeding. It’s a simple at-home screening tool to help detect issues before they become serious.
["A simple, painless screening test to detect hidden blood in stool, often used for early colorectal cancer detection."]
Key facts at a glance
- LOINC
- 11898-4
- Short code
- GA from BPD
- Synonyms
- GA from BPD
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- us-estimated-from-bpd
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Colorectal cancer is one of the most preventable and treatable cancers when detected early. Hidden blood in stool can be a sign of polyps, ulcers, or cancer in the digestive tract. This test helps catch problems before they cause symptoms like changes in bowel habits, pain, or bleeding.
How It Works
You collect a small sample of stool using a provided kit and return it to your healthcare provider. The test detects human hemoglobin, a protein found in blood, using a chemical reaction that changes color if blood is present. Results are usually available within a few days.
What to Expect Before the Test
No special preparation is needed for this test. You may want to avoid certain foods or medications that could interfere with results, such as red meat, vitamin C supplements, or certain blood thinners. Always follow your healthcare provider’s instructions.
What to Expect After the Test
After collecting the sample, you can dispose of the kit as directed. If you experience unusual symptoms like severe pain, black stools, or vomiting after testing, contact your healthcare provider immediately.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results may indicate hidden blood in the stool, which can be caused by conditions like hemorrhoids, inflammation, or colorectal cancer. Negative results do not rule out colorectal cancer, so follow-up testing (such as a colonoscopy) may still be recommended based on your risk factors. Always discuss results with your healthcare provider for personalized guidance.
Short name
FIT (Fecal Immunochemical Test)
Frequently asked questions
What does a positive result mean?
What if I have no symptoms but test positive?
Can I eat or drink anything before the test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy