Are you in an area where you can seek another opinion from a different pediatrician? Or, can you ask your pediatrician for a referral to a GastroEnterologist?
Something isn't right, and it isn't normal. Pediatricians are very well trained at palpatating the abdomen to find abnormalities in organs, etc. But, if I were in your shoes, I'd want to know what the source was as well.
One word of caution if you're using the internet to search her symptoms, it can be the source of great information and really awful information. I'd only seek information from recognized medical institutions or organizations (for example: seeing information from the American Diabetes Association for a related matter).
That's my best advice.