MY HUSBAND IS HAVING ANNOYING PAIN IN HIS RIGHT CHEST

mY HUSBAND IS HAVING ANNOYING PAIN IN HIS RIGHT CHEST AT THE BOTTOM OF HIS RIB CAGE AND IT IS NOT A HEART PROBLEM. HE WAS TESTED FOR IT MANY YEARS AGO AND THEY FOUND NOTHING BUT THE PROBLEM IS RE-OCCURRING OFF AND ON AS HE AGES AND HE WANTS TO GET TO THE BOTTOM OF WHAT IS CAUSING IT.