My lo has diarrhea for 4 days. Went to pd and kkh they only can give probiotic.. Any remedy available? LO is 7m old. Butt is red and painful with rash...

My LO had stomach flu 3 weeks ago. Also had diarrhea. Butt was red too. PD prescribed lactofort (probiotics) and for diet, she said jus plain porridge with fish. Don't add veggies yet . Don't give fruit yet too. As for milk, either convert to soy formula or half strength milk first. As for the butt, we apply organic pure virgin coconut oil.. It is v effective.