After eating, I am experiencing stomach bubbling, nausea, bloating, and cramping. Everday after meals for the past 3 weeks my stomach feels a bit whoozy, which makes me begin to feel nausea. Several times I have experienced diarrea, and my stool color is a light brown (caramel color). I've also experienced a pressure and eye irritation in the back of my eyes. I've tried taking Pepto Bismo and laxatives, but these are just temporary relievers. What might be the cause?