Last Updated on Mar 10, 2016


Colonoscopy is the most sensitive test for colorectal polyps and colorectal cancer.

Screening tests are of importance in detecting polyps before they become cancerous.

  • Faecal occult (hidden) blood test: This is primarily a screening test for colon cancer. It doesn’t help in diagnosis of polyps that do not bleed.
  • Flexible sigmoidoscopy: A slender, lighted tube is used to visualise the rectum and sigmoid. The sigmoid is approximately the last 2 feet (61 centimetres) of the colon and is where nearly half of all colon cancers are found. It doesn''t detect polyps elsewhere in the large intestine.
  • Barium enema: This helps to evaluate the entire large intestine with an X-ray
  • Colonoscopy: This testis similar to flexible sigmoidoscopy. It offers the advantage that the entire colon and rectum can be visualised. It is the most sensitive test for colorectal polyps and colorectal cancer.
  • Computerized tomographic colonography (CTC) or virtual colonoscopy: This is a new technique that may make colon screening safer, more comfortable and less invasive. It may not be as accurate as regular colonoscopy. Sufficient data is not yet available.
  • Stool DNA testing: This new technique is primarily designed to detect colon cancer. It is yet to be certified by the Food and Drug Administration.
  • Genetic testing: A person with a family history of colon polyps is a candidate for genetic testing.


  1. Cecil Medicine, 23rd Ed.
  2. The Merck Manual, 18th Ed.
  3. Mayo Clinic

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