Even though you don't have gallstones, could you be having gallbladder trouble? I'd ask your doctor about that. It could also be severe indigestion or heartburn. Have you tried --- and please know that I realize you are in big pain and this is a simple answer--- an OTC acid reducer like Pepcid or Tagamet? Since you saw a doctor for the procedure to rule out gallstones, what did they suggest for a cause and your next step?