Colon Cancer Screening

Colon and rectal cancers (often referred to collectively as colorectal cancer) are malignancies (life-threatening tumors) that develop in the large intestine.

Colorectal cancers usually occur in people over 50. Women -- particularly African American women -- are more likely to develop colon cancer while men have a higher risk for rectal cancer. Family history, use of alcohol, smoking, and other intestinal disorders all play a role in your risk factor for colorectal cancer.

Screening tests for colon cancer are extremely important for detecting premalignant polyps and colorectal cancers at stages early enough for complete removal and cure. Only a minority of adults over 49 years old has regular screening tests that could detect a cancer early enough for curative treatment.

A survey reported that many people were not screened because they were too embarrassed and revealed that they would rather lose months off their life than face these tests. Those who had already had the tests were willing to have them again if they saved one additional day of their lives. Do not be afraid to discuss these screening tests with your doctor. Several screening options are available:

• Digital rectal examination
• Stool examination
• Sigmoidoscopy and/or Colonoscopy

Digital Rectal Examination. The digital rectal examination is used to detect tumors in the rectum, lower intestine, and prostate gland. The doctor inserts a lubricated-gloved finger into the patient's rectum and feels for lumps or other abnormalities. The exam is quick and painless but embarrassing for some and far from accurate.

Stool Examination for Occult Blood. Blood in bowel movements is not always visible, in which case it is called occult blood. Fecal occult blood tests (FOBT) are used to detect this hidden blood. The most common FOBT method is called the guaiac-based test. The patient is asked to supply up to six stool specimens in a specially prepared package. This test is far less accurate than other methods.

Colonoscopy and Sigmoidoscopy. If a digital rectal examination or stool sample show signs of trouble, several methods to visualize the colon are available, including sigmoidoscopy, colonoscopy, or a double-contrast barium enema. Sigmoidoscopy can only view the rectum and the left side of the colon, while colonoscopy and barium enemas allow a view of the entire large intestine. Both flexible sigmoidoscopy and colonoscopy involve snaking a fiberoptic tube through regions of the rectum and colon to view the walls of the intestine. During either procedure, the physician is able to remove polyps or other abnormalities revealed by these procedures.