The most reasonable initial evaluations have already been performed. I would suggest considering tests to evaluate the gallbladder function - which can be done via a HIDA scan with CCK stimulation. Some studies have shown that patients with a low gallbladder ejection fraction may benefit from a cholecystectomy.
Other tests to consider would be a 24-hr pH study, looking for GERD (although this would be an atypical presentation) or tests for the pancreas (via imaging studies like a CT scan and pancreatic function tests like amylase and lipise - this too would be an atypical presentation).
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.