Bowel Cancer Test, Colon Cancer Test, FOBT, Fecal Occult Blood Test

FAECAL OCCULT BLOOD-BOWEL CANCER TEST

Question 1. What is Faecal Occult blood Test (FOBT)? 

FOBT is a test used to screen for early signs of cancer of bowel (colon & rectum) in stool. Bleeding is one of the early signs of bowel cancer. In very early stage, bleeding from the gut may not be visible to your eyes and FOBT detects signs of bleeding before it is visible to naked eyes. 

 Questions 2. How is this done? 

Usually your provider will give you a kit with instructions to follow. Various FOBT kits are available on the market. Some can be done at home yourself following instruction provided while others will require you to send sample to the medical laboratory. To increase chance of detection, the tests are repeated on 3 different days. Only a small sample is required for the testing. If some cases, you can mail samples to your provider or the lab.

The samples will be tested for blood. The laboratory uses antibody specific for Human Hemoglobin, released by red cells from bleeding in gastrointestinal tract. The results are reported as negative or positive.

 Question 3. What does the test result mean? 

Negative result mean there is no evidence of bleeding from your gut and chance of cancer is unlikely. You may repeat your screen after 2 years unless your doctor indicates that you need to repeat that earlier than this. For example, you have previous history or have one member of family known to have bowel cancer. Positive test would mean that there is evidence of bleeding and that you may need to discuss with your doctor to see if you require further investigation to exclude bowel cancer. It does not mean you have bowel cancer. However, positive FOBT individual is 12 times more likely to have bowel cancer than someone who has negative FOBT.  

 Question 4. What will my doctor do if I have positive FOBT? 

Your doctor will review your result with all other information you provide and his own findings on clinical examination to decide if you will require referral for further testing. Generally, you will be referred for colonoscopy or Barium Studies if your doctor feels that it is important that bowel cancer be ruled out as a cause of positive FOBT.  You are more likely to have colonoscopy if you have the following;

You have complaints suggestive of bowel cancer (weight loss for unknown reason, abdominal pain)

One of your family member is known to have bowel cancer

Your doctor cannot find other causes of positive FOBT

You have had history of previous cancer or precancerous lesions (polyps)

Positive Blood Bowel Cancer test (CEA)

 Question 5. What is the best sample? 

The best sample is a fresh stool taken first thing in the morning. This is usually concentrated and the detection rate for diseases are much better than that taken any time of the day.

 Question 6. Is there any problem with this test?

FOBT detects presence of blood in stool. Any condition causing bleeding from gut can interfere with the test. This is why you need to discuss with your doctor whether or not the test is appropriate for you. Accordingly to a study in UK, FOBT only picks up about 50-60% of cancers.  The test is invalid if there is obvious blood in stool. In this case, the evidence of bleeding is already visible and a colonoscopy or Sigmoidoscopy is required.

 Question 7. How long can I wait to repeat my FOBT?

It is recommended that FOBT screen must be performed every 2 years beginning at age 50. Screening should start earlier and done more frequently if you have strong family history of bowel cancer or have history of colonic polyps. Note, if you have more than one of your family members with bowel cancer or you have precancerous lesions (polyps), colonoscopy is recommended every 5 years in addition to FOBT.

 Question 8. Where can I get more information?  

Visit your local doctor or contact us and we will provide you will more information. See also CEA testing on this website.