I worked in an Endoscopy Clinic for a short time after retiring from the hospital where I had worked for 17 years. And I've had 2 (thankfully only 2) colonoscopies myself. On a personal level, I hate them. I had no bad results, but the prep is totally not fun, as anyone who has done it can relate, but the worst part about the whole experience for me was the hassle with the insurance companies and the billing department at the place where I had it done (local hospital).
The way it's coded determines how it is paid for by the insurance company, and the reason why it is being done is part of how it gets coded. One insurance may pay for it at a higher rate if it is coded as being done for a certain reason while another insurance company will not pay for it at all if coded the same way. So check with your insurance company on how they pay and under what circumstances. Then talk to the doctor and/or billing person about getting it coded to allow better coverage by your insurance company. It saved me thousands getting an incorrect billing code corrected, but it was a huge hassle after the fact. Colonoscopies after a certain age are supposed to be covered as a basic screening, but if it's not coded correctly the insurance company may reject payment.
Thankfully, my doc has determined I don't need to have another one for at least 10 years, which I may well stretch out to the rest of my life. Same goes for mammograms. Hate them, and now I've been told I won't have to have one for another 10 years and I don't plan on ever having one again, if truth be told. Well, of course that is dependent on remaining symptom-free. And I am 70, so would not at all suggest such a laissez faire attitude to young women.