Just thought I'd add what happens to me - I can eat a very small amount of dairy once a day - I can have a small amount of grated cheese, or 1 tbspn cream etc providing that is all the dairy I have that day but I can never, ever have it cold. Icecream (even soy icecream) or cold soy choc milk always brings on a severe attack. When I was under the care of a nutritionist this really threw a spanner in the works as it didn't fit the diet parameters I was on. It was only ages later that I worked out it was the cold. Not sure why and it doesn't matter if I have had IS or a IBS safe meal first.