My daughter is 1 1/2 and ive noticed everytime she drinks her lactose milk she gets diarrhea all day and same with regular milk.. However she can eat all dairy products perfectly fine. It only effects her when she drinks any type of milk straight. When she was a baby she was on dairy free formula but hasnt been on a bottle since 11 months. we switched to lactose and tried regular milk and noticed its only when shes drinking it is she getting stomach aches and diarrhea. She doesnt have any issues with ice cream which is odd! Im so confused. We have moved her to almond milk for now but I think its so weird.