1. That's not bruised ribs. If you had bruised ribs, you wouldn't be able to squat, unless you're completely immune to pain. Then again, this is from personal experience from seeing others with bruised ribs. And I highly doubt a belt could cause that. There may be bruising on the skin outside of your ribs, but the actual bone is not bruised.
2. How long has it been bothering you? Have you given it sufficient time to rest? Have you RICE'd it?
3. How much are you putting up?
4. Can you deadlift without any irritation?
5. What kind of pain is it? Throbbing/stabbing/etc