L., personally I wouldn't change the diet exactly, but would look at one thing at a time. First thing, what is she drinking? I know with me, one day all of a sudden Cow's milk does this to me. It didn't use to, but now it does. Normally, it makes children constipated. Another thing to think about is...now this may sound weird, but sometimes when people have diarrhea, it's actually a symptom of being constipated. Go figure!
Also, if she is drinking juice of any kind (which is really of no nutritional value)..that too isn't good for her either.
Another thing is wheat...allergies to food can all of a sudden pop up.
I asked a few of my friends and I'll post them here but in different paragraphs:
My son went through this at about the same age. My dr had his stool tested but was pretty certain that it was the rotavirus. She said it could be picked up anywhere and just to make sure he was hydrated. He had it for about 2 weeks before I took him in. From what I remember he then still had it for at least another week, maybe 2. Also, I remember hearing something once about modifications to the BRAT diet in that it was important to consume foods with lots of fiber and fat. Something about absorbing the excess moisture in the guy. I don't remember changing my son's diet...I just had to let it run its course. I believe the tests did come back positive for rotavirus.
If this was my child, I would give her acidophilus (a lot) to make sure that the probiotics in the intestines were doing well and then I would also make sure she wasn't constipated. I know that sounds the opposite, but sometimes
when people are constipated they get "diarrhea" because that is all that can get past. My kids enjoy dates and dried prunes, they are delicious! Along with that, they eat all kinds of other fibers. These are just some ideas I
My 23 month old has several allergies with staggeringly different symptoms. For corn, it's diarrhea. Oats is a 12+ hour tantrum, food color is general crankiness. Haven't discovered what's causing the recurrent eczema on her legs.
Well that's about all of the suggestions right now. I hope this has helped a bit. I would definitely get some probiotics into her body and just resume a normal diet. I would keep away from cow's milk and juice for now and just give her good water to drink, which is the best for her anyway. But as you reintroduce other foods back to her, notice how each food product affects her.
Also, did the doc test her for a virus? Just curious. HTH!