Persons over 50 years old and without family or personal history of cancer are considered of average risk and we recommend colonoscopy at that age and subsequently every 10 years if normal. But if it is abnormal, then more frequent tests may be needed.

Those with moderate to high risks, which include family members with colorectal cancer, may need colonoscopy even earlier - at the age 10 years earlier than the youngest family member with colorectal cancer.

2. Can a screening test tell if I have colorectal cancer?

It depends on what the screening test is. Colonoscopy is the most accurate and should be able to detect colorectal cancer directly. Other screening tests like faecal occult blood test (FOBT) and barium enema is less accurate and may still need a colonoscopy to confirm.

3. How accurate are the different tests - FOBT; sigmoidoscopy (a procedure in which the doctor looks inside the rectum and the lower part of the colon through a lighted tube); DCBE (a procedure using barium and air to look at the inside of the large bowel) and colonoscopy?

Colonoscopy is the most accurate way of screening. This is followed by the DCBE, sigmoidoscopy and lastly FOBT.

If DCBE detects any abnormality, a colonoscopy is still needed to confirm this. Sigmoidoscopy only inspects the left colon and will miss lesions on the right side.

FOBT only detects blood in the stool. As the cancers do not always bleed, some cancers can be missed.

4. Are colorectal cancer screening tests uncomfortable, and how do I prepare for these tests?

Before going for a colonoscopy, you must take a laxative to clear any faeces. The colonoscopy itself is reasonably painless as it is usually done under sedation. Occasionally you may feel some bloating or uncomfortable swelling in the tummy area.

5. Who will perform the tests and interpret the results?

The colorectal surgeon and gastroenterologist (a medical doctor who specialises in treating diseases of the digestive system) can perform such tests and interpret the results.

6. Are screening tests covered by insurance companies and medicare?

This depends on the insurance policy you have. Colonoscopy is usually claimable from Medisave.

7. Are screening tests worth the cost and discomfort then?

Yes - as these can save your life!

8. If a screening test finds a polyp, how will it be removed?

Polyps found during colonoscopy can usually be removed especially if it is less than 2cm. Larger polyps may need a formal re-section of the colon.

9. Are 'at home' screening tests for colorectal cancer accurate?

No, they are not and cancers can be missed.

10. What should I do to prevent colorectal cancer?

Besides regular screening tests, a healthy diet and lifestyle are very important in colon cancer prevention. You may want to consume adequate dietary fibre. We recommend 25 to 30g of dietary fibre a day. You should also limit the consumption of fat and get plenty of exercise.

Smoking and alcohol are also associated with colon cancer.

Some research have shown that taking aspirin, folic acid and vitamin E on a regular basis may be preventive too.

~ A Straits Times Article