I'm lactose intolerant as well, but over the past few years have been working on building up the good bacteria in my gut again. My doctor told me that if you develop lactose intolerance as opposed to being born with it, you can somewhat fix it. I certainly can't drink a milkshake without being in agony, but I can have yogurt and baking and a little bit of cheese without adverse effects.
Because some of IP's products have whey or dairy, I did have some discomfort in the first few days but seemed to be fine after a couple of weeks. I do take a lactose pill with some things like the Mango Shake though. I do find that in general I'm far less bloated and (ahem) gassy than I ever was before IP which is a nice side effect!
Are you able to take the lactose pills?
I agree with the others here in asking your coach, as there are products that don't have anything that should affect you negatively if you're lactose intolerant.
Good luck and keep us in the loop!