I had a similar experience to
@slowmotion. The first one I opted to have no sedation after discussion beforehand which suggested that "older patients tend to have a higher tolerance to discomfort", and your recovery is quicker without. It was OK actually. The second one was a follow up as I needed more polyps removed, and it was going to be a longer session, so opted for sedation. It was a similar experience to the first except that I felt a bit more chilled, and I was kept under observation for longer before they let me go. The whole experience was very professional and inspired confidence.
I've had a few procedures over the last few years, various scans etc but this was a fairly benign experience.
Hence my saying that the bowel prep was the worst part of the procedure. If you are going to have the screaming squits, it's always better to be in control of when you want it to start. Once you start, it's self limiting. Still, a man's gotta do what a man's gotta do. I don't think the taste of it had even registered as an issue. I had dysentery in 1990 and remember thinking then, "when will it ever end?" When I dragged myself to the doctor when it was finally safe to stray far from the toilet, he said he'd had it too. He was retired and working as a locum. "Had it in Pune when I was an Army doctor in India during the war. It was much worse this time!" he'd said.
The bowel prep was a minor inconvenience compared with that.