Welcome to this great forum that has tons of very good info and an awesome group admin. 🙂
I am glad you got a referral to a GI. They are normally much more helpful and knowledgable than peds.
I suggest that when you see him, ask his opinion on adding in a supplement of digestive enzymes and probiotics for your little one. The dr may not know much about them but some doctors do and highly recommend them. Here is my story about how they helped my children.
https://www.infantreflux.org/forum/forum_posts.asp?TID=16038&PID=123639#123639
Everyone is different and what helps one child doesn’t always help the next but I’d sure say they’d worth giving a try.