If you are 50 or over or have a family history of colon cancer, you should be screened. African-Americans should be screened beginning at age 45. Colon cancer is one of the most preventable and curable types of cancer when detected early. Since the risk of colon cancer increases with age, getting screened is essential.
Following a clear liquid diet the day before the test, an preparation is taken that "cleans" out the colon. There are a variety of newer preparations that are better tolerated than previously.
The procedures are done with sedation (not general anesthesia) and there should be no pain experienced. A long, thin tube with a camera at the tip is inserted into the rectum and the instrument is passed all the way through the entire colon to the point where it meets the small intestine.
If you have a family history of colon cancer or colon polyps (premalignant growths that emerge from the colon wall), then you are at a higher risk. There are a variety of other conditions such as inflammatory bowel disease (Ulcerative Colitis and/or Crohn's Disease) that place a person at higher risk for colon cancer as well. Colon cancer screening should always be discussed with your doctor.