Summarize the following:
For the general population (those who have not been designated to be at a heightened risk of colon cancer), screening is recommended to commence at the age of 50. The options to consider are a stool test (recommended once every one to two years), a colonoscopy (a more invasive test that is recommended every 10 years), or a sigmoidoscopy or CT colonography (both of which are recommended every five years. The one you choose for your own personal screening will depend upon your preference. Both blood and/or DNA can be tested for in your stool, and a positive test indicates suspicion that you may have colon cancer. It does not indicate that you have colon cancer - it simply means that you are at a heightened risk and should undergo more extensive medical evaluation. The advantage of stool testing is that it is an easy and non-invasive test. You can collect the stool sample(s) at home (depending upon how many are requested by your doctor) and simply send them into the lab for formal evaluation.  A stool test that is positive for blood and/or for DNA indicating possible colon cancer requires further follow-up exams. It does not mean that you have cancer, but it indicates the need for further testing. A stool test that is negative means that you are at a very low risk of having colon cancer and do not need any further investigations at this time. Stool testing is recommended once every one to two years, if this is your chosen form of screening for colon cancer. A colonoscopy is an alternative method of screening for colon cancer; it is much more invasive than a simple stool test, but also more accurate. During a colonoscopy, a small tube is inserted through your rectum and passed all the way through your large intestine. There is a camera and a light at the end of the tube, allowing your doctor to see whether or not there are any lesions in your colon that are suspicious of being possible colon cancer. You normally need to take medications to induce diarrhea prior to the procedure in order to clear out any stool from your colon. You also normally receive light sedation for the duration of the exam, and you will not be able to return to work for the remainder of the day following the procedure.  The advantage of a colonoscopy is that it is very effective at picking up any suspicious lesions (more effective than a stool test). This is why you only need one once every 10 years, as opposed to once every one to two years for the stool test. The disadvantage of a colonoscopy is that it is a more complex and invasive procedure. Most people opt for either the stool testing or the colonoscopy as a means to screen for colon cancer. However, some less common methods that are also available include a sigmoidoscopy (where a tube is inserted through your rectum, but it is a shorter tube that only examines part of your colon), or a "CT colonography," which is where you receive a CT scan looking at your colon.  The disadvantage to a sigmoidoscopy is that it does not look at your whole colon. (The advantage is that it is less invasive than a full colonoscopy.) The disadvantage of a "CT colonography" is that, if a suspicious lesion is noted, you will need to subsequently undergo a colonoscopy so that your doctor can see it first-hand. (The advantage is that the procedure is not invasive.) Both of these screening tests, if you opt for them, are recommended every five years. A fecal occult blood test is the most common method that doctors use to screen for blood in the stool.  If you have blood in your stool and you are losing weight or anemic, then you may need a colonoscopy.

Summary:
Begin screening at the age of 50. Opt for a stool test. Get a colonoscopy. Consider other modes of screening.