---

• n  visual examination (with a sigmoidoscope) of the lower third of the colon in a search for polyps

• Fifty is also a good age to have a sigmoidoscopy, in which a doctor inserts a flexible tube into the lower third of the colon to look for polyps or tumors.
• If you use one of the less definitive tests-- a flexible sigmoidoscopy, barium enema or simple stool analysis--you should get tested more frequently.
• A sigmoidoscopy, the most commonly recommended screen for colon cancer, misses about half the precancerous polyps spotted by the more costly colonoscopy, which probes the entire .

• flexible sigmoidoscopy