Lucky for you that you can eat whatever you want and that you find a way how to relief the pain.
Anyway it is very hard to say what could be causing your abdominal pains without making some diagnostic procedures like: standard blood test, Helicobacter pillory serology, ultrasound scan and gastroscopy.
IBS could be one of the possibilities but let us first exclude gastritis, peptic ulcer, chronic pancreatitis, gallstones, diverticulitis etc.
You can consult some gastroenterologist.