How far out from surgery are you? I assume if your surgeon is willing to do an endoscopy (he's correct that it's the best way to view the wrap), I'm sure he'll be more than careful to do it without harming anything. That was always my concern.
I had one done about two and a half years out on the request of my asthma doc, who wanted to be sure my lung issues were a result of my allergies, not a failed wrap. I went to a surgeon in our new city, he checked it out and said all is fine. I actually had the works--barium swallow, manometry, endoscopy, and 24 hr PH monitor. I guess he wanted to be sure to have a complete picture. It's good, though. Now I'll have a surgeon up here, in case I should ever need one.
I do agree with your assumption that the esophageal irritation could be from food sitting at the wrap site. I suggest you discuss the pros and cons of dilation before your endoscopy. You'll want to have thoroughly discussed the ramifications before you're out cold, he goes in, and decides to dilate you. I would expect a good explanation of why and possible consequences.
Now, I'm just assuming that is a possibility because if your irritation is caused by food at the wrap site, he'll want to help move things through.
I would ask how likely he thinks it is that your wrap will loosen on its own.
I may be jumping the gun and assuming a possibility that won't occur, but just in case, you might want to think about it.
I'm sure you'll be glad to find out what's going on. One of the toughest things about recovery is the not knowing.