help for woman in mid-20s with undiagnosed g.i. problems

I am trying to help an acquaintance searching for a diagnosis for her mish mash of g.i. symptoms. Diarrha, constipation, weight loss (I don't really know what else). She is in northern California and has tried docs here and in L.A.

Any suggestions? Should she go to Cleveland or Mayo? If yes, who should she see? I don't want to send her to Dr. Shen since he is a j-pouch specialist.

Thanks,

Debbie