My daugther have diarrhea 20 x day what shall i do?

Need more info: You do not say how old she is or what other symptoms she may have, whether she is in day care or otherwise exposed to GI viruses like norovirus. The major thing to do is, if she is older than one, is to try to stop the diarrhea with something like Imodium (loperamide) (see your pharmacist) and keep her well hydrated and clean her bottom off between movements with moist towelettes, and perhaps use an ointment.