I've been doing the calcium chewables for awhile now and they don't seem to hurt my stomach - are you taking yours with food? That might help. I've tried calcium gummies and also the chocolate-flavored chews and both of those seem find on my stomach, so maybe give a few different types a try and see if anything works better for you. Also, make sure you're taking vitamin D and magnesium along with your calcium - those will help your body absorb it better.
I'm lactose intolerant as well but there are a lot of dairy substitutes out there. Right now I'm doing a lot of cashew milk - I really like the flavor and creaminess of it. I also do a fair amount of goat cheese - it's tasty and doesn't affect my stomach the way that cow dairy does, it's fine for me. It's a bit pricey but I like it better than the cheese alternatives out there - I've tried things like soy cheese, rice cheese, etc. None of those seem to melt well, like on a pizza. Goat cheese does melt well on a pizza, so it's been my go-to for awhile now. I wouldn't recommend other goat products though - I once tried goat yogurt and couldn't even swallow a bite, it had such a strong (and nasty) flavor, I nearly threw up.
I do soy yogurts and those are fine.
Another thing to try, if you're well enough and able to, is to do some weight-bearing exercises to keep your bones healthy and strong. If you are able to exercise, start out slowly with light weights to see what you're able to do, and gradually increase the weight and reps and intensity from there if you're able to. You don't even need to use weights necessarily, there are a lot of good bodyweight exercises such as push-ups, squats, lunges, etc that can help prevent bone loss.
I hope that was helpful! Good luck!
