My Friend Is 65, Has Ha Three Stints And Some

my friend is 65, has ha three stints and some serious kidney problems, works construction every day. i watch him suffer from a serious pain on the outside of his lower calf bone not muscle he said to the point he can not even stand. Dr's he has seen say they can not find anything, had catscan mri and check for clot. nothing. is also on blood thinners and blood pressure medicine. can you think of anything that it may be, or what he should do, no brace is even working...