My friend experiences pain while running, I can't figure it out and his doc can't either.?

I have a friend who used to be a little...heavy, but in the last 2 years he has lost about 100lbs through diet and exercise, and P90X. He ran regularly, until a few months ago when he began experiencing sharp pain in his legs and feet. I am a cross country and track runner so thought I could help. His description sounded like shin splints (I know firsthand the feeling of shinsplints), but icing and rest have not helped. He has seen doctors and bone specialists who told him to rest 2 months, but it persists when he tries to run again. He tried insoles, which helped temporarily. He is pretty much ready to quit running altogether. He told me today his calves/shins feel like "trying to squeeze a watermelon into pantyhose". Icing, insoles, and doctor attention haven't helped. I'm wondering if he has stress fractures or stress reactions. Any thoughts?