[CFW]

Of course a colonoscopy doesn’t prevent colon cancer. However, it can help detect it by finding the polyps which may be cancerous a lot earlier than waiting until severe symptoms arise. Most people are not going to immediately go to the doctor when they suspect a problem. They will assume the problem will resolve itself. Who really wants to discuss their bowel issues with anyone, even their doctor. That leads to a late diagnosis which results treatment in being undertaken too late to get rid of the cancer cells before they spread. Get your regular colonoscopy done as recommended by your treating physician, especially if you are feeling discomfort and having problems with your daily “constitutional” or seeing bloody dark spots in your stool.

[TangoLimaSierra]

Of course a colonoscopy doesn’t prevent colon cancer. However, it can help detect it by finding the polyps which may be cancerous a lot earlier than waiting until severe symptoms arise.

Article doesn't say colonoscopy was to prevent cancer. Did you read it?