I'm wondering if lactose intolerance can cause nappy rash? DD (2 years old) loves her milk, but the more she drinks the worse her bottom gets! When I tried weaning her from formula onto cows milk at 1 year old she got a terrible bum and we had to stick to formula until she was about 15 months. Then we managed ok for a while on cows milk but now she likes to drink a lot of milk and seems to have a rash most of the time. Does this mean she's lactose intolerant? We're trying soy milk for the first time this week. She likes it which is a good start! But I'm worried that I don't really know much about soy milk and whether she will be getting the same nutritional benefits as she would form cows milk. We've chosen a calcium-fortified brand.