I've had an endoscopy twice and it was fine. The first time, like you, I was dreading the thought of it wondering how you could not possibly gag on it. It was done at a BUPA hospital, I saw the dr. on a Tuesday and he said he could fit me in on the Thurs. No way. I needed to think about it. I asked if I could have a general anaesthetic and he said it wasn't worth it, it only took about 10mins. He said he would give me valium and put me last on the list. When it came to having it done, I told myself if I wasn't 'out', I would just get off the bed. I was paying for this and I was going to be in control. I then had sedation and as far as I was concerned, I didn't know any more about it, I was asleep. They deny this and claim you're not asleep, you just don't remember. You can respond to their instructions like swallow please altho' you have no knowledge of it. I would say the worst part was the lignocaine they sprayed in my throat. The dr. claimed it tasted like bananas but it was foul. There was no pain, no aftereffects and the second time I had one done, I couldn't have cared less.