Your daughter seems to be having allergy to certain food types, owing to which she feels bloated and has lower abdominal pain. Rifagut and nexpro are only temporary solutions. You need to get to the root of the problem.
Next Steps
I would start with a food allergy test, a simple blood test which will diagnose which food stuff she has allergy to. In addition to this, I would also recommend an endoscopy both of the stomach and proximal part of the small intestine and the large intestine. You need an experiences endoscopist who will be able to identify the problem and take biopsied from the intestine.
Health Tips
Avoid food stuff that causes this problem in the meanwhile.