I have right-sided pain most days lately. It started w/ an ovarian cyst that was found during an ultrasound...they also found 2 small gallstones. But my GP said neither can really explain the type of pain I have. My gallbladder is apparently healthy looking but the pain often stems from there. It's just this dull ache and at times feels like it's maybe the muscles in that area...I even find that when I walk or move it hurts like a muscle would. Many of us seem to get unexplained aches/pains that stem from the abdominal area...there are so many GABA receptors in the stomach that have to heal, so apparently it is all very normal - but I also know how unsettling it is. I've had pains in the past (lower abdominal) that were so bad I'd double over in pain but then at the doctor all would be fine. SO strange.
I hope this passes for you soon. Just find comfort in knowing it is "normal" during benzo w/d to have stomach issues of all kinds. If all came out fine at your doctor, then try to deep breath when the pain comes on and tell yourself "it will end...it's just my body healing". I know that's easier said than done, but I find the more I tell myself the quicker I calm.