Colon cancer starts as a precancerous growth called a polyp.
Most polyps do not cause any symptoms until they turn into cancer which takes about 5 to 10 years. Yes, because colon polyps and colon cancer may occur in younger people, but at a much lower rate. A screening colonoscopy is an exam of the entire colon with a lighted flexible tube containing a camera-like device at one end, called the colonoscope. Most do not remember having the test performed because you are consciously sedated with strong pain medication and relaxants. A colonoscopy usually takes about 20-30 minutes.