I've got trouble with casein too, so I avoid all dairy. A tiny bit doesn't do much, and it is the lesser of my woes, but it's insta-headache, some stomach troubles, and messes with my sinuses. Not fun.
Some people do eventually reintroduce things their intolerant to, but I think it really depends on the person. I can't have soy either, and don't expect to ever get that back.
If it's just lactose you have problems with, though, then it is more likely that you'll be able to reintroduce it eventually.
I was also thinking possible dairy problems, but it could be a bug. Last week I was under the weather and concluded it must have been CC aftereffects, but one of my coworkers had the exact same thing, sooo...
Could also be the unfortunate effects of healing, Our guts tend to be fussy for a while. Too much something could have upset it.
In any case, good luck and hope you feel better soon!
You don't have to go into gory details, but don't have to have a "ladies don't poop" attitude either. My man picked up some sort of stomach bug on vacation and it was pretty nasty for a few weeks. He didn't want to describe it but I'm like "man, you have no idea the stuff I hear on the celiac forum, so you really can't gross me out". He's like "How do you put up with this all the time?"
But really, saying you feel like crap and get stuck on the toilet for an hour is really all the mental picture you need to give. If you SO is understanding, that's all he'll need to hear. Don't go into more detail than you're comfortable with, but don't be afraid to scare him away (cause if you do, then he wasn't worth it anyway).