My three months old daughter has diarrhoea and there is mucus in the stool. what should be the treatment?

3 yo and diarrhea: Has she been on antibiotics - if so - probably best to take her to a doctor to be checked if not and if this an acute issue - probably the best is to put her on a clear liquid diet - apple juice, jello, gatorade or pedialyte or water ice is fine. If she tolerates this - gradually increase her diet to a brat (banannas, rice cereal, applesause, and dry toast) no dairy though for several days.