Shaddy, which Mayo are you going to? Rochester, Jacksonville or Scotsdale? You really must present a difficult conundrum of symptoms for Mayo (especially if it is Rochester) to be this long in Dx'ing the cause or causes and proposed treatment. I've found thru 50 years of vists to Mayo, Rochester, that they are the EPITOME of efficiency as well as the tops in Gastroenterology and other specialities. They are known for not leaving any stone unturned.
IF you could just once even see the films from say a CT Enterography done at Mayo w/in just a few weeks of one done locally you would understand and see for yourself how their state of the art equipment and experienced radiologists and techs can reveal and detect so much more than our locals.
You really are in the best of hands at Mayo and I hope you get some answers soon!!!! (((hugs))) and God bless!