Well I know what you went through with the endoscope! Im from Leeds in the UK and have had two endoscopies done! The last one I really thought I was going to die, I could barely breath, I remember them saying "relax Mr Parker" as I lunged at the attending Doctor! In some cases they like to rely on the natural peristalsis that takes place when swallowing, thats why they like you alert and not sedated. Although my first endo was ok I was sedated and cant really remember it!
Anyhow drop me a quick email if you wanna chat! I may have a diet that might work for you!
I have to go for surgery some time this year, but as you well know here in the UK the waiting lists are long!!
Let me know how you are getting on!