I don't eat much dairy, I have dairy free yoghurt, milk and butter but I do have ice cream and chocolate which cause no reaction. Same with, for example, a jar of curry sauce that has milk in it.
When I eat cheese, within about 10 minutes I get diarrhoea, have to run to the toilet and feel like I'm about to be sick and get tummy ache and then within an hour it passes and I'm totally fine again. It's usually cheddar or Parmesan.
Everything I've read online seems to suggest reactions take a few hours with lactose intolerance and that cheddar and Parmesan are low lactose and that ice cream is high lactose. Is there something else in the cheese that I could be having a reaction to?