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Colon Cancer Screening: Fecal Immunochemical Test (FIT) for Occult Blood (24-Hour Specimen)

Published: August 9, 2026Updated: August 16, 2026

This test detects hidden (occult) blood in your stool over a 24-hour period, helping screen for colorectal cancer or precancerous changes.

Quick summary

["A simple at-home test to check for early signs of colon cancer or polyps."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
111956-9
Short code
Dx and macro find Colon Endscpy
Synonyms
Dx and macro find Colon Endscpy
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
endoscopy
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

What the Test Measures

The FIT test identifies microscopic amounts of blood in your stool, which may come from polyps, early-stage cancer, or other gastrointestinal issues. This blood isn’t visible to the naked eye but can signal problems that may need further investigation.

How It’s Collected

You’ll collect a small sample of stool using a provided kit, typically at home. The sample is then mailed to a lab for testing. No special preparation is needed, but avoid using certain medications or foods that could interfere with results.

Why It’s Done

Regular screening with FIT helps detect colorectal cancer early when treatment is most effective. It’s especially important for people at higher risk, such as those with a family history of colon cancer or those aged 50 and older.

What to Expect After Testing

If your test result is positive, your healthcare provider will likely recommend additional testing, such as a colonoscopy, to investigate further. A negative result means no visible blood was detected in this sample, but ongoing screenings are still advised.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

FIT (24h)

Frequently asked questions

How often should I get this test?
Most guidelines recommend this test every one to three years, depending on your age, health history, and risk factors. Follow your healthcare provider’s advice for the best schedule for you.
Can I take any medications before the test?
Yes, some medications—like nonsteroidal anti-inflammatory drugs (e.g., ibuprofen) or certain blood thinners—may affect results. Ask your doctor if you’re unsure about any medications you’re taking.
What does a positive result mean?
A positive result means hidden blood was detected, which could indicate a problem like polyps or early cancer. Further testing is needed to determine the cause, but early detection is key to managing the condition effectively.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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