I just had endoscopy performed on Thursday, February 26. I was so nervous, but I was pleasantly surprised to find that the medication they gave me intraveneously quickly put me out. I don't remember a thing! They say we are not completely under and that the dr can speak to us and we respond, but the medication has some kind of amnesia effect. So try not to worry!
Upper endoscopies are very easy.... on you the patient, I mean. They put you under light sedation on a table with bunch of docs around and you bite down on a plastic tube thing to keep your mouth open while you 'sleep'. Then, bam, you wake up! At most, you'll have a sore throat for a few days. You'll be a bit groggy the first day, too. They can do so much via endoscopy these days and it's all very new and exciting. Much better than the old days where the option would be exploratory surgery.
Good luck