Did she have any other pelvic or abdominal surgeries prior to her gallbladder surgery?  I suggest doing some research on Adhesion Related Disorders.  Many doctors don't know much about this or don't believe in the pain or problems caused by adhesions.  I had peritonitis in 1998 due to a ruptured ovarian dermoid cyst.  Now it appears the complications from the peritonitis and postsurgical adhesions have come back to haunt and torture me this past year.  I also had my gallbaladder out in June after much difficulty diagnosing my digestive troubles.  I eat a low fat diet and also follow the DASH diet for my kidney problems and I even recently went to a low residue diet because eating has become incredibly painful most days.  When I get really miserable I go liquid for a few days.  I have a bowel movement every day so I  get really frustrated when doctors want to simply call it IBS and prescribe pills.  I  really feel your girlfriend's frustration.  It is very difficult and requires a lot of discipline to restrict one's diet.  Especially when you are losing weight, underweight, and not getting adequate nutrition.  I've have been through the specialists this past year and am now on to a Nephrologist for my kidneys.  I will discuss with him whether my digestive disturbances are from an inflammatory condition resulting from the severe intrabdominal adhesions I most likely have.  The next step is to consider Adhesiolysis and find a surgeon willing to help me.  I have found most help and compassion going to Emory, a teaching hospital in Atlanta.  Try to find the "best" doctor for her.  My prayers for her finding relief soon.

Have they checked her for ulcers by any chance via an EGD?  I just found out I had ulcers and the pain you describe is very similiar.  I would have never thought it could hurt like that either.

You should post the question on the regular forum where the doc will answer.