Why does 2% milk make me sick?

I've drank 2% as a kid with little sickness and now when I drink even a small 8oz glass of 2% I get sick to my stomach. My wife has drunken whole milk her whole life and when she got pregnant the Dr. told her to switch to 2% but that only made her nausea worse. Even now (our baby is 8 months) when she drinks 2% milk she will be in the bathroom sick all day. She switched us to organic whole milk and we were fine. Could we be lactose intolerant now? (but we can eat cheese and other dairy products no problem) or have our bodies grown sensitive to the hormones and other products they pump into the cows?