I have never had cancer of any kind in my family tree, and I had a precancerous polyp found at 38yo.
You should get a colonoscopy. If you are at low risk and look totally healthy after, they'll tell you that you don't need another for a good while and you'll get the benefit of not (often) getting something that you don't think you need and, as a bonus, not die of treatable cancer.
You'll die of something else then. That's the part that so many people seem to overlook.
There is a money-making industry around colonoscopies and mamograms. I'm not saying to disregard medical advice in this regard as for any individual there may be good reasons to have these procedures. However you can't completely discount the financial incentives for the providers.
You should get a colonoscopy. If you are at low risk and look totally healthy after, they'll tell you that you don't need another for a good while and you'll get the benefit of not (often) getting something that you don't think you need and, as a bonus, not die of treatable cancer.