Twenty-four years ago, I ruptured my esophagus on a flight (which is a guaranteed way to get the full attention of the flight attendants!) I gagged on a piece of lettuce and will spare the details of the next few hours

. After that for a couple of decades I had to have my cardiac sphincter (the one at the top of the stomach) resized every year or two. I've had more EGDs than I can remember, but I do remember early on I found that if they didn't give me lots of happy juice, my body would fight them every step of the way.
I am a world-class gagger! I'd wake up with memories of gagging and my throat would be sore for days. After a few rounds of that, I would tell them (because of my work, we moved around a lot, so I've had plenty of docs ream me out!) that they had to go heavy on the sauce, and if they actually listened to their patient, we all had a good experience.
Speaking of technique, I found one doc in South Carolina who had the magic touch! He would have me sit on the edge of the table, then he'd spray the back of my throat with banana-flavored kerosene and while I was gagging from that, he'd slip that snake down my throat and back out before I knew what was happening!! He was incredible!!
If you have an experienced doc and a good medical team, you have nothing to worry about. Just relax and it'll be over before you know it.
BTW - when I had my RNY, the surgeon must have fixed the condition that caused all the trouble, because I have had no problems or symptoms since!! YAYYY!
CT