If you're lactose intolerant, you'll want to limit or cut out dairy foods that cause problems. Look for lactose-free versions of those foods. Using an enzyme product such as Lactaid may help as well.
Also try other calcium sources, like fortified soy milk, almond milk, or other products that have calcium added to them. Canned salmon and leafy greens also have a lot of calcium.
Check with your doctor to make sure you get enough this important mineral in your diet.