Skip to content

    Colorectal Cancer Health Center

    Font Size
    A
    A
    A

    Stool Tests for Colorectal Cancer

    Stool tests may be used to check for colorectal cancer, but they are never used to diagnose it. Other tests for colorectal cancer include flexible sigmoidoscopy, colonoscopy, and CT scan (virtual colonoscopy).

    A stool test is one of many tests that may be used to screen for colon cancer. Other tests include sigmoidoscopy, colonoscopy, and computed tomographic colonography. Which screening test you choose depends on your risk, your preference, and your doctor. Talk to your doctor about what puts you at risk and what test is best for you.

    Colon Cancer: Which Screening Test Should I Have?

    Health Tools

    Health Tools help you make wise health decisions or take action to improve your health.

    Why It Is Done

    Stool tests are done:

    • To look for signs of cancer.
      • FOBT and FIT/iFOBT tests look for blood in the stool. These tests are useful to screen for colon cancer, because tissue or polyps with cancer are more likely to bleed than normal colon tissue. If bleeding is found, more tests will be done to find the cause. It's important to call your doctor if a home test shows blood in your stool. A home test doesn't replace the need for a regular exam by your doctor.
      • Stool DNA tests look for abnormal changes. Colon cancer cells often contain DNA changes in genes. Cells with these changes can be shed into the stool, where this test may be able to find them.
    • As part of a routine physical exam for those with a higher chance of getting colorectal cancer, especially at age 50 and older.

    How To Prepare

    Since colorectal cancers do not bleed all the time, FOBT and FIT/iFOBT tests are done over several days on different stool samples. This increases the chance of finding blood in your stool if it exists. A stool DNA test requires only one sample.

    You may need to avoid certain foods for 2 to 3 days before the test. This depends on what kind of stool test you use. If you aren't sure, ask your doctor.

    WebMD Medical Reference from Healthwise

    Last Updated: November 14, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

    Today on WebMD

    Colorectal cancer cells
    The right diagnosis is the most important factor.
    man with a doctor
    Our health check will steer you in the right direction.
     
    sauteed cherry tomatoes
    Fight cancer one plate at a time.
    bladder cancer x-ray
    Do you know the warning signs?
     
    bread
    ARTICLE
    Colon vs Rectal Cancer
    VIDEO
     
    New Colorectal Treatments
    VIDEO
    can lack of sleep affect your immune system
    FEATURE
     
    Cancer Facts Quiz
    QUIZ
    Virtual Colonoscopy
    VIDEO
     
    Picture of the Colon
    ANATOMY
    Vitamin D
    SLIDESHOW