DD can drink normal milk without dramas now but we did have to do lactose free for the intestine detox. I think with my DD it was a reduced ability to digest fattier cow's milk stuff like cheese/yoghurt ITMS. I did reduce her dairy intake. Maybe with the BFing if you consume a lot of dairy that could have an impact too? If in a few days it hasn't cleared then it's probably best to seek a second opinion.