pain under left ribs ...

My 11 yr old son has something gi related going on. He's been getting sick (vomiting) after eating for a while now, 6-9 mo's, it was infrequent, usually with chicken tenders or nuggets so we cut those out, then it started with other food, plain pasta with parm, or pizza, fries ... and now cereal in last 6 weeks or so, now it happens almost every day after almost any type of food. He's a horribly picky eater so ruling out much will be a challenge but we will do what we have too. But the pain under left rib just started a few weeks ago.

Pediatrician did blood work and checked for Celiac, it was negative. Other blood work was Ok. Doing stool test this week. Had an appt for a pediatric gi specialist this week, Friday, Nov 20th.

No fever but he says he feels hot., it actually runs below norm -- 97.4 or so.

He's never been a sickly child and all of sudden this. He's missing a lot of school ... and that only makes things harder.

Right now he's on per his pediatrician:
Antibiotic (for 2nd bout of strep in a month) -- dr has changed this antibiotics to make sure he's pain wasn't a side effect, no change

Raglan, Prilosec, probiotic and Zofran as needed. I can't say I have seen a change.

I'm concerned and want a fix. Hopefully the gi dr will help. Any thoughts?