sure.
I had previously had an upper gi endoscopy with sedation, and I felt groggy and useless for rest that day. Then I couldn’t sleep that night, and felt jet lagged and tired the next day. So I was very motivated to avoid sedation.
I had both an upper and lower procedure when I had the colonoscopy. The upper was very unpleasant, because I gag and wretch. If I had been inclined to bail, that’s when I would have. The colonoscopy was tame in comparison.
I don’t actually remember if the bailout option-in was sedation or “go home”. I’d guess it was sedation, but I can’t swear to that.
The scope felt crampy when they inserted it. At one point, the nurse suggested I might want to grip the railing of the bed, to better cope, and i did that. But it was less painful than the part of labor (for childbirth) that happens before they offer you anesthesia. Unpleasant, but a level of pain that’s well within what most people can endure.
They shove the tube all the way in, to the end the large colon, and actually do the exam as they extract it. That part was painless. You fart some, because they pump you full of air so they can see better. The actual exam was fun, because I got to watch, and they explained what they were seeing. I suppose if they found anything it might have been scary, but my colonoscopy clean.
The scope itself is fairly narrow, and they use lots of lube, so the insertion and extraction of the scope is easy. I think the part that is uncomfortable is the air.
I am not especially inclined to painful gas cramps. When I get gas, it mostly just goes through me. (Although a had a bad experience with too much apple juice once, so I have had gas cramps.) I think i may have had easier time than someone who routinely finds gas painful. And maybe if you have an especially fragile colon it would hurt more.
When it was over, I was shocked at how easy it had been, especially as compared to early labor. And I was left puzzled as to why the standard is to sedate people.