A referral to a gastroenterologist is a reasonable option. Possible causes can be irritable bowel disease,
inflammatoryInflammatory bowel disease
Ulcerative colitis bowel disease, dyspepsia (i.e. GERD, an ulcer of inflammation of the upper digestive tract), or liver/gallbladder problems.
Further evaluation can include an upper endoscopy as well as an abdominal ultrasound to evaluate the liver and gallbladder. A colonoscopy can be considered to evaluate the lower GI tract.
The pancreas is a possibility - and can be evaluated with blood tests looking at the amylase and lipase. The CT scan would appropriately evaluate for any calcifications that can be suggestive of chronic pancreatitis.
These options can be discussed with your personal physician or gastroenterologist.
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.
Kevin, M.D.
http://www.straightfromthedoc.com
http://www.digestivedistress.com/what_is_GP.html
Gastroparesis can be a complication of diabetes. That link has a lot of info on other things, too.
I'm sure Dr. Kevin will reply soon.