You said your daughter has always had runny stoolls, this could be normal for her if she has no other symptoms like rashes, poor weight gain, sleep disturbances frequent gas. A big clue is the appearance of the stool (gross I know) is there stringy mucous in it or dark specks or obvious blood? The very smelly thing might be an indication. Unfortunately if you suspect a food allergy the only way to do it yourself is eliminate foodsone by one. It can take up to two weeks to clear their system, if it is a long term allergy exposure (something they eat every day it could take as long as a month or more to see better stools (usually though you see it is getting some improvement before then) The big things to start with are what they call the top eight like milk, soy, eggs, fish, wheat citrus, corn, tree nuts/nuts. Remember if you go this route, you have to read labels especially with milk and soy and corn as these are ingredients in many things and go by many names, milk can be whey,casein etc.. and soy is hydrolized veggie protein, natural flavours etc... all these things would have to elimenated to do a proper trial.Since your daughter is two, I believe they can do allergy tests so I advise seeing a doctor if you are really convinced. Stick to your guns if you think it is an allergy, because if she appears otherwise heathly it is my experience doctors take a stand back approach. I will state this could be normal for her thoughtwice a day is not bad and can be normal. I'm not a doctor but hope this was helpful. I know there ae lots of links out there for allergies, even in this forum.