The fact that you have a fever says that there is definitely something wrong with you. Have you had the breathalyzer test to check for bacterial overgrowth? And did they take a stomach sample when they did the endoscopy to check to see if you have h.pylori?
Hopefully Sarita will be along shortly. She too has had problems with running a low grade fever and has had nothing show up as wrong with her on tests--even when she went to the Mayo Clinic. She also suffers from very bad diarrhea. One of her doctor's nurses tried her on an antibiotic on the off chance that it would work and it did help her quite a bit. She's still not normal, but things are (or at least were, last I heard) manageable for her.