I've had three colonoscopies since October 2011; during that one, an enormous polyp (pre-cancerous) was found in my descending colon near my anus. Since then, two more; second one found pre-cancerous polyp (tiny) in transverse colon; third one found benign tiny polyp in ascending colon. I had an upper endoscopy two days ago and it took longer than the colonoscopy. The propofol hit me hard, I was "stoned" all day. My Gastro Dr. wants to do another colonoscopy in three years (my third was June 25 2014). I will be 70 years old then. I am in excellent health: no heart disease, no arthritis, no bad joints, I ride horseback 3x a week and passed the stress echo with flying colors. What are the odds that I will develop a pre-cancerous polyp that will produce a cancerous tumor - how long does that take? I really do not want to take propofol again, I think I may be developing a reaction to it, I am unable to take many, many medications.
It can be a tiresome procedure to do. However, before making a decision risk versus benefit should be weighed.
You mentioned one polyp was precancerous. What about the other two? We're they regular benign polyps with no malignant potential. Also is there a family history of colon cancer?
If the polyps are benign and no family history, you could consider foregoing colonoscopy and continue with an active and healthy lifestyle. Incorporate good amount of fiber in your diet. The choice will have to be yours as no one can decide for you.
It's hard to predict how long does a precancerous polyp takes to become full blown cancer. The biological behavior of atypical cells and cancer cells is still not a very well understood science. At 70 you may develop a polyp which may never kill you and mortality may be due to other causes. Or it may be extremely aggressive. As I said it will be pure speculation to try and judge course of polyp evolution.
Given all the conditions and your lifestyle you can make an informed decision.
I wish you good health.