Is LPR really it's own thing or not?

[Imajerk]

There seem to be articles and all sorts of things indicating LPR as a separate issue from GERD. My gastroenterologist heard me and said "Oh, is that a separate thing now?" meaning he was skeptical, and I guess thinking that true medicine is not considering symptoms that people file under LPR, as separate from GERD.

I did read on some general site that there is a debate in the medical community over whether throat symptoms or even respiratory are a separate diagnosis vs GERD without them. What's the deal? Has anyone really, objectively studied it?