Boyfriend having abdominal pain

Ok so my boyfriend has been to the er 3 times over that past like 6 months for pain in his lower right abdomen. I've had my appendix removed so I suggested that could be the cause but every time he goes to the er they can't seem to find anything wrong with him. He's in so much pain it makes him cry. Idk what else to have him do. He doesn't have insurance so going to a primary doc or a specialist right now can't happen. He's been using my heating pad for now but it's not helping much. And the er doesn't prescribe him anything since they can't find anything wrong. Any suggestions??