ASK THE EXPERT: Is that a polyp in your intestine?
Ella Tan | On 02, Feb 2015
Hence, it is usually not possible for someone to know if he or she has a polyp based on symptoms alone. The following are the common tests available in Singapore for colon polyp detection:
1. Stool occult blood test. This test is commonly used for colon cancer screening, but it is very poor for detecting polyps, with a detection rate of 25-65% only for large polyps. However, it is the cheapest and easiest test available. In future, the new DNA stool tests may provide higher detection rates for polyps.
2. CT colonography. This is a special CT scan for the colon, and is one of the recommended options for colon cancer screening. It is 90% accurate for picking up polyps larger than 10mm, but the accuracy drops to less than 50% for small polyps < 5mm. Also, any finding on CT scan needs to be verified with a colonoscopy.
3. Colonoscopy. This is considered the ‘gold’ standard for polyp detection. However, there is still an overall ‘miss’ rate of 20-25%. This is primarily due to ‘operator’ factors, or the quality of the procedure performed by the doctor. By definition, colorectal cancer affects the colon or large intestine. This is the most common type of digestive cancer. Cancer (a similar type of cancer cell) can also arise from the small intestine. However, small intestine cancer is very rare, and accounts for only 1% of digestive cancers.