My daughter suffered through 4 Clostridium difficile infections (bacterial overgrowth in large intestine), and Rifaximin (Xifaxan) was an effective treatment. Other antibiotics (Flagyl, Vancomycin) made her very very ill. Eventually we did a microbiome transplant and that cured her. Along the way we discovered a fructose intolerance that produces a lot of the symptoms you listed. That was discovered through a horribly uncomfortable breath test (drink a fructose solution, breathe into a tube to capture gasses). I wish you the best of luck caring for your wife. The Mayo Clinic is a wonderful place because of their "whole patient/grand rounds" approach. By the way, there is usually High Fructose Corn Syrup in bread. You have to read the labels. If you are interested in knowing more about fructose intolerance, reply to this and I'll share all I know. I am always happy to help others because so many kind strangers helped us.