FOBT (Fecal Occult Blood Test)
FOBT is a screening test that mainly finds colorectal cancer and bleeding polyps at an early stage when the chance of being cured is high. Polyps can bleed and larger polyps are more likely to bleed than smaller polyps. So, if there is occult (hidden) blood in your bowel movement it could be due to a bleeding polyp or colorectal cancer. FOBT can detect hidden blood in your bowel movement. If you have a positive (abnormal) result, you will need to have a colonoscopy to determine what is causing the blood in your stool.
To be considered effective, a FOBT must be done every year. If it is not done every year, this test is not as effective.
How do you do the FOBT?
Your healthcare provider will give you a FOBT kit to take home and complete, which includes instructions and supplies you will need.
- Use the stick or brush from the kit to collect a small amount of stool from a bowel movement. It takes a few minutes to collect the stool sample.
- Depending on the type of FOBT kit you are given, you will need to collect either 1 or 3 consecutive stool samples.
- The FOBT requiring only 1 stool sample is commonly used in your community.
- For the FOBT requiring 3 consecutive stool samples, collection may take a couple days.
- Depending on the type of FOBT kit you are given, you might need to change your diet before doing the test. Ask your doctor if you should change your diet.
- Put stool sample(s) in the tube or on the card provided.
- Put completed tube or card in the mailing pouch that is provided and mail it through regular postal service to your healthcare provider’s office or lab where it is checked for occult (hidden) blood.
Benefits of FOBT screening
FOBT helps detect bleeding polyps that are cancerous. Therefore, colorectal cancer can be found early when the chance of being cured is high.
- This test is done in the privacy of your own home.
- No bowel preparation is needed for FOBT.
- There is no risk of bowel perforation during the FOBT.
- In general you do not need to stop blood thinner medications.
- It is a less expensive test.
Risks associated with getting FOBT
There are almost no risks to the FOBT. However, potential risks are:
- This test may not find most polyps or all colorectal cancers
- About 5 in 100 people will have a positive (abnormal) test. A positive (abnormal) test does not mean they have colorectal cancer, but they may need to have a colonoscopy