microbiome products

Immunochemical Fecal Occult Blood Test

Immunochemical fecal occult blood test (iFOBT, or FIT)


A fecal occult blood test (FOBT) is a laboratory test to check for the presence of hidden (occult) blood in a stool sample. Occult blood in stool may indicate colon cancer or colon or rectal polyps -- although not all cancers or polyps’ bleed. Usually, occult blood is excreted in very small amounts and can only be detected by the chemicals used in fecal occult blood tests. If the fecal occult blood test detects blood, additional tests may be needed to determine the source of the bleeding. A fecal occult blood test can only detect the presence of blood and cannot determine the cause of the bleeding. Fecal occult blood testing is not recommended if you have symptoms of colon cancer. See your doctor if you notice blood in your stool or toilet, or if you experience abdominal pain or a change in your bowel habits.


Risks and limitations of the fecal occult blood test include:

Tests are not always accurate. If your cancer or polyp is not bleeding, your fecal occult blood test may show a negative result (false negative result) when the cancer is present. When you don't have cancer, your test may show a positive result (false positive result) if you have bleeding from other sources, such as stomach ulcers or hemorrhoids.

Having a fecal occult blood test may result in additional tests. If your fecal occult blood test comes back positive, your doctor may recommend an examination of the inside of your colon, such as a colonoscopy.

What should I avoid before an FIT?

Before an FIT, you do not need to make any dietary changes, but you do need to avoid certain medications. NSAIDs and blood-thinning medications may change the results of your test. Your health care team will let you know what medications to avoid before taking the test.

How to Collect Fecal Sample

  • Write your name, age, sex and collection date on the sample tube.
  • Place Collection paper in toilet bowl.
  • Twist and open sampling bottle.
  • Scrape the fecal surface from side to side.
  • Insert the sampling probe into the bottle and click.
  • Enter sampling bottle into Sample Bag and return your sample.

Informed Consent Form for Testing
The signed informed consent form should be returned to the laboratory with the FIT tube.

Basic criteria for rejection of samples

  • Unlabeled or incorrectly labeled specimens.
  • Specimens received without a consent form (request form).
  • Specimens’ improper containers.
  • Specimens in leaking containers.

Specimen Stability
Ambient: 7 days

Reference Interval
Negative cutoff  < 100 ng/mL
Positive cutoff    ≥ 100 ng/mL

Report Turn-around-time (TAT)
Upon receipt of the laboratory (cutoff time is 16:00): Next working day.

Your doctor will review the results of the fecal occult blood test and share the results with you.

Service Order
If you are interested, please contact us at 2903-0700

Contact Us
G-NiiB Molecular and MicroBiome Laboratory*

Unit 902, 9/F., 208 Johnston Road, Wan Chai, Hong Kong

Office Hours
Mon-Fri: 9:00am - 6:00pm (Lunch hour: 1 - 2pm)
Sat, Sun & Public Holidays: Closed

(852) 2903-0700 during office hours

*accredited by the Hong Kong Accreditation Service in 2024