What is this test?
The test looks for very small amounts of blood in the stool that are not visible to the naked eye. The method can be immunochemical or chemical according to the kit used.
Why might it be ordered?
- As part of screening for colon cancer and polyps in asymptomatic people according to age and guidelines.
- To check for hidden bleeding when anemia or other symptoms suggest it.
What sample is needed?
At home, collect a small stool sample using the supplied kit. Follow the instructions exactly and do not contaminate it with urine or toilet water.
How should you prepare?
Preparation depends on the method. Do not change your diet or medicines unless the kit instructions or your clinician specifically tell you to. If you are menstruating or have visible bleeding, ask when to collect the sample.
How should you understand the result?
A positive result means that blood is detected, but does not indicate the source and does not necessarily mean cancer. Further evaluation is usually needed. A negative result does not rule out all polyps or periodic bleeding.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.