Your symptoms do not sound like food allergies.
Possibly, food intolerance, which effects the digestive system.
There are a slew of gastrointestinal diseases that can cause the symptoms you are experiencing (ie:colitis, irritable bowel synsrome, diverticulitis, crohn's disease, and list goes on).
Have you to tried an elimination diet to see what may be causing your symptoms?
I would personally seek out a gastroenterologist first and if nothing is found, I would then follow through with an allergist.
Very similar things happen to me when i eat onion which i also have an allergy of. I would recommend getting tested for food allergies over the foods you eat most often to start with ex(milk, eggs, wheat, yeasts, soy, sugar) and then go from there. I would also find an allergist that does blood testing for allergies and not just skin testing. I was skin tested for food allergies and it came up with only wheat for me. Then i was blood tested and 12 different allergies popped up. So im a huge advocate of blood testing for food allergies.