They won't knock you out, unless you're in a hospital....otherwise, they use Versed, and it doesn't work on everyone. My DH had versed when he had a colonoscopy and he said that the pain went up into his chest. Found out later, that he had had a heart attack..
This was at the VA and they didn't catch it. He died, in another hospital, 2 months later, from another heart attack. He was in the hospital for something else, but they could not save him.
MY Father died from colon cancer, but I will never have a colonoscopy, because of what happened to my Husband.....and I will never have versed again, because of his and my bad reactions to it. (my BP shot way up, at the dentist's office), obviously his did too, but instead of stopping, they went on and he had the heart attack.
Judy, an MRI sounds good..