I found out I was lactose intolerant about a year ago, and since then I've been drinking Lactofree milk, which fixed the problem, until now. I had a glass of this Lactofree stuff a couple hours ago and now I have diarrhoea and intense stabbing pains in my intestine area. This was the effect of normal milk until I stopped drinking it. It was a new carton and it wasn't out of date. What do?