Stomach, Digestive & Bowel Disorders

I started having discomfort/pain in my right side, just below my ribs a little over two weeks ago.  I saw my Dr. yesterday and he poke and prodded where my gallbladder is an it hurt.  He was pretty sure it was gallstones and ordered an upper right quadrant abdominal ultrasound.  I had that this morning, when she pressed down it hurt like she was pressing on a bruise.  The scan showed not stones and now I have an appt with a gastroenterologist a week from today.  I have no diarrhea or constipation but have been gassy, I start belching right after I eat and this afternoon I had the worst gas pains I have had in a long. The intestinal gas started a couple weeks before the pain, I tried some peppermint tea and it helped some. 

I have a history of endometriosis and when ever i had gastro issues (fairly mild) my doctors would tell me that frequently ibs and endo went hand in hand.  I was able to control most of my issues with diet but would have some issues with my period.  Things have been pretty calm with my digestive issues since hitting menopause two years ago (at age 41). 

Any ideas what this is and what kind of testing the gastro is going to want to do?  Any info or advise would be appreciated