Remedies for 1 year old lactose son?

Karen

My son hasn’t been drinking milk for the last 2 months and I feel he needs the nutrients from it every time I give him milk he gets diarrhea so I been giving him rice water all this time which I boil rice and water I strain it and save the water in the fridge I thought he was lactose free so last night I bought him lactose free milk and right now he had diarrhea what could it be any one had this happen to you guys. TIA