Any idea what this could be???

So I am pulling my hair out now!
Sam already has a severe egg allergy and is dairy intolerant. We have had her on Soy formula for a few months now and all has been going pretty well since getting all the dairy out of her system.
About a month or so ago she developed a majorly bloated tummy (we are talking like the starving kids on the tv) that starts right under her ribs to the point where it actually is pushing them out slightly. She was really irritable and wouldn't eat, plus really runny poos. Then one day she started vomiting. Just for the day. A couple of days later the tummy went down, the bloating went away all was good again. A few days ago it has all started again. First the bloating, then the vomiting for a day.
I can't pinpoint a particular food she has eaten that might have caused this and she is so miserable. We haven't had a solid poo from her in so long I can't remember, she is really grouchy all the time and obviously has a sore tummy being that bloated. She hardly eats anything, but will still take her bottles (she has 2 a day).
Any ideas. Could this be a gluten/wheat intolerance/allergy or maybe she has developed problem with the Soy.
I am taking her to the doctors this week to get his opinion, but just wondered if anybody has been through anything similar? Help

That is what i am afraid of

It sounds like something is upsetting her bowels. A lot of people with undiagnosed gluten intolerance can develop a lactose intolerance (similar to dairy but not quite the same). Was she tested for gluten intolerance? It sounds like there is some other food irritating her digestive system, poor thing.