I've had this 3 times because my father died from stomach cancer at 34 yrs. Its not that unpleasant - they gave me mild anesthesia......sometimes I wasn't aware and other times aware but didn't mind. Only uncomfortable thing is when they 1st put the tube down, but you might be put out completely. Last time it was funny because the doctor asked me if I wanted to see my own stomach and I said yes lol.

I'm sorry you're worried about the drinking and its affect on your esophagus - I pray you'll be okay. Have they also felt your thyroid gland - enlarged thyroid can sometimes affect swallowing. I also get an adverse reaction from anesthesia - makes me very restless, so you need to tell them about this beforehand. Its not a bad procedure and better to know than not treat it it all. Best of luck and hope it goes well splitimage.