Talk to Gastroenterologist on Digestive Problems

it's been a year now I feel nauseous almost every day n lately I'm observing that my stool doesn't look healthy everything is d same d way it's eaten my body doesn't break down food I feel. I don't know which doctor to see for ds kind of problem plus I want to know if any tests or somthing so dt I can figure out if I have some food allergies or intolerance