My son (who is allergic to milk) always had very hard stools, and it's something we still battle with from time to time, even though he's 6 and a half. We had spoken to a dietician when he was about 18 months, and I must say that although limiting fat and soda in your home is great, it likely has little or no effect on the constipation. What your daughter needs is fluid and fibre (you may know this already). Make sure she drinks enough (water is the best ... yah, right!) - try to avoid to many dairy products which can be constipating, too. You are right that carbonated drinks are not good, but especially caffeinated ones such as coke, mountain dew, and some root beers. Fibre is the tough one! I add bran and/or wheat germ to everything from his morning cereal (1TBSP or so), to meatloaf, hamburger patties, casseroles, etc. (and it's good for the rest of us to help prevent certain types of cancer, right!?). This seems to work wonders for him, and I can really tell if he's missed a day or two of his bran in the morning! Constipating foods include all dairy products (cheese, yogurt), bananas, apples,(and any fruit that is high in pectin, actually) and rice. If you get really desperate, there's always prune juice .... IF you can get them to drink the stuff! You may already know all about this, but I thought I'd mention it just in case. Blessings.