I finally recovered from my colonoscopy , which really isn't all that bad. Everybody over 50 should get one. In Ontario, you can go to a clinic which charges $80 over standard OHIP, and you get far better service, as well as pretty pictures.
The day before, you've got to take laxative bombs, and on the morning you are starving, but that's standard for any procedure. They give you some very nice drugs, and soon it's all over.
The advantage of getting one is that they can snip nasty growths right away and check them in the lab. If you are all clean and shiny, you only need one every 5 years. It's the best way to practically totally prevent colon cancer.