For colon cancer screening, you will be given the test to use at home. Be sure to follow the instructions provided. Most tests have the following steps:

• Flush the toilet before having a bowel movement.
• Put the used toilet paper in the waste bag provided. Do not put it into the toilet bowl.
• Use the brush from the kit to brush the surface of the stool.
• Touch the brush on the space indicated on the test card.
• Add the brush to the waste bag and throw it away.
• Send the sample to the lab for testing.
• Your health care provider may ask you to test more than one stool sample before sending it in.

You do not need to do anything to prepare for the test.

Some people may be squeamish about collecting the sample. But you will not feel anything during the test.

Blood in the stool may be an early sign of colon cancer. This test is performed to detect blood in the stool that you cannot see. This type of screening can detect problems that can be treated before cancer develops or spreads.

Talk with your provider about when you should have colon screenings. If you are age 45 to 75, you should be screened for colorectal cancer. There are several screening tests available:

• A stool-based fecal occult blood (gFOBT) or fecal immunochemical test (FIT) every year
• A stool DNA (sDNA) test (Cologuard) every 1 to 3 years
• Flexible sigmoidoscopy every 5 years or every 10 years with stool testing by FIT done every year
• CT colonography (virtual colonoscopy) every 5 years
• Colonoscopy every 10 years

A normal result means the test did not detect any blood in the stool. However, because cancers in the colon may not always bleed, you may need to do the test a few times to confirm that there is no blood in your stool.

If the FIT results come back positive for blood in the stool, your provider will want to perform other tests, usually including a colonoscopy. The FIT test does not diagnose cancer. Screening tests such as a sigmoidoscopy or colonoscopy can also help detect cancer. Both the FIT test and other screenings can catch colon cancer early, when it is easier to treat.

There are no risks from using the FIT.

Immunochemical fecal occult blood test; iFOBT; Colon cancer screening - FIT

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Lawler M, Johnston B, Van Schaeybroeck S, et al. Colorectal cancer. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 74.

Patel SG, May FP, Anderson JC, et al. Updates on age to start and stop colorectal cancer screening: recommendations from the U.S. Multi-Society Task Force on colorectal cancer. Gastroenterology. 2022;162(1):285-299. PMID: 34794816 pubmed.ncbi.nlm.nih.gov/34794816/.

US Preventive Services Task Force, Davidson KW, Barry MJ, et al. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA. 2021;325(19):1965-1977. PMID: 34003218 pubmed.ncbi.nlm.nih.gov/34003218/.

Updated by: Todd Eisner, MD, Private practice specializing in Gastroenterology in Boca Raton and Delray Beach, Florida at Gastroenterology Consultants of Boca Raton. Affiliate Assistant Professor, Florida Atlantic University School of Medicine. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.