abdomen cramping possibly from gerd fundoplication surgery?

Hi, I think have a failed fundoplication done in 2001. Gerd symptoms returned and symptoms are only partially controlled with significant meds. It likely failed in 2007 and I had full round of testing outside of the ph/motility study last year. Upper GI was only somewhat indicative of a potential slip, but not conclusive and endoscopy was not conclusive either... which was surprising to me.   Revisited the surgeon who was not able to say for sure, so I'm left hanging. Anyway, a strange and troubling symptom has developed since my symptoms returned which neither my gastroenterologist nor surgeon are familiar with. I have a distinct cramping/pulling pain in the area of the operation that is definitely made worse in the sitting position. The gastroenterologist tried a couple of gastro "relaxer" meds with no luck. However, I take xanax for occasional anxiety and this definitely helps a lot. Could there be some kind of muscle tear or other "irritation" from the fundopliocation that is relieved by the body relaxing effects of xanax? Anybody have experience with this? Thanks in advance for any helpful info.