I wasn't lactose intolerant until shortly after I was diagnosed. Lactaid tablets worked fine for me, also...and then they didn't. I could only tolerate a small amount of hard cheese if I took the tablets. Overnight (and I'm not exaggerating) I could no longer drink Lactaid milk, and I couldn't handle lactose free products. I became dairy intolerant that quickly! It's been a year, and I still can't tolerate anything with dairy. Just sharing this with you because I didn't believe it could happen quickly, but it can.
Hey gilligan-- Here is 'My" personal theory. When my Celiac was triggered, it also triggered a lactose intolerance that remained after healing. When I removed the gluten for some time (months), I could still react to the lactose specifically. I kept it out of my diet for several weeks, yet now, almost ten years later, I can handle some in slim moderation without the tell-tail bloat. I do love cheese. :-/ Others can handle it with no problem when the villi heal.