After the participants have undergone the informed consent process, they will have 30 milliliters (approximately two tablespoons) of blood drawn. This will be done prior to their scheduled screening or diagnostic colonoscopy. If the patient has indicated a desire to receive the results of their test, they will receive a written description, as will their primary care physician. The patients will be contacted yearly for up to 5 years by the study staff to learn whether they have been found to have a diagnosis of colon or other cancer.
