I had it done twice, both times without sedation by choice. I did have analgesics, and a cannula in my wrist in case I changed my mind mid-way.

It was quite tolerable, just a few moments of short lived cramping pains (similar to diarrhea pains) as the endoscope turned the corners of my insides. My recovery was about half an hour of sitting up and having tea and toast, while those that were sedated slept off the drugs.

I'd do the same again if ever I get another one, and recommend it to anyone who can't have or doesn't want sedation.