I just had a gastric endoscopy a few months ago and I was given the choice when I booked, to have either conscious sedation (which I know from bone marrow biopsies does NOT work on me, and just means I'd have to stay at hospital for hours afterwards) or the throat numbing spray. So I chose the spray.
And I must say, be SURE you fast exactly like they tell you. I thought it was so they could see the contents of your stomach properly, but really it's so you don't projectile vomit all over the room. For real, you just dry heave continuously for the entire procedure, with this open ball-gag type thing keeping your mouth open. It was definitely one of the more horrible things I've had done to me in the past year. And I didn't even have the "up the bum" one!