My girlfriend has a pain on her left side in the middle of her rib cage. says the pain is similar to the cramp like pain you can get after running?

Sounds like: Something is inflamed and irritated. She can try Ibuprofen 4 every 8 hours or aleve (naproxen) 3 twice a day then if it doesn't improve she can see the doctor.

Muscle cramp: Cramps can be caused from exercise, electrolyt imbalance and damage to the muscle. We don't have a great way to treat them but often resolve on own. Potassium can help (bananas) if it doesn't resolve in a few days see a physician.