What other tests are available for screening of colorectal cancer?
a. Fecal occult blood test plus a flexible sigmoidoscopy has been recommended every 5 years. In this test, stool samples are collected in a small plastic container and analyzed in a laboratory for the presence of blood. The flexible sigmoidoscopy can only assess the lower rectum and colon for polyps. Both these tests can miss a lot of cancers and false positives can occur (conditions like hemorrhoids and rectal ulcers may also bleed). Data reveals that this test only prevent 12-16% of colorectal cancers. b. Flexible Sigmoidoscopy every 5 years The sigmoidoscopy can only evaluate the bottom 20-24 inches of colon and rectum. The scope is inserted in the rectum and generally does not require sedation. The technique is not very sensitive for screening colon cancers and data reveals that it may miss 15-20% of colon cancers. c. Double-contrast barium enema every 5-10 years Another technique which has been used to screen for polyps is a double contrast enema. In this study, barium is inserted
