The whole reason that screening colonoscopies are done at all is that colon cancer is a major cause of morbidity and mortality, and screening has been shown to reduce each of these numbers. Colonoscopies work as a screening tool because research studies have shown that colon cancers develop through a life-cycle typically involving growth as a polyp. These polyps can range in size and shape throughout the colon; those that have the potential to grow into a cancer are referred to as adenomatous polyps. When polyps are removed during a colonoscopy
, they are sent to a pathologist
who examines the cells under a microscope. If pre-cancerous changes and cells are confined to the polyp that was excised, then the risk of cancer in that particular area is significantly diminished. If your physician finds adenomatous polyps in your colon, then typically a colonoscopy is repeated in 3-5 years to make sure no new adenomatous polyps have developed in the interim. If several large adenomatous polyps are found, your physician may elect to repeat a colonoscopy within 1-2 years. If non-cancerous polyps are found (such as hyperplastic polyps) then your physician may elect to perform repeat screening in 5-10 years. There is really nothing an individual can do to make sure they don't come back, other than ensuring regular follow-up with your physician and undergoing the recommended screening guidelines.