Have you recently had blood work done for Celiac disease? If not I would.

Also a negative U/S does NOT rule out gallbladder problems. You should also have a Hida Scan done. If it is negative then your gallbladder is okay. My problems were found on Hida Scan after I had a negative U/S.

http://www.mayoclinic.com/health/hida-scan/MY00320