This is a very interesting post. It was originally thought that there was little to no bacteria in the small intestines. Now with capsule endoscopy physicians have been able to see more and more of the small intestine and are finding there is bacteria in there. At least more than previously thought, though I feel much more research is needed.
Have you considered that your problem may not have been the probiotics, rather, anaerobic bacteria? The very last thing you took was Metronidazole (Flagyl) which is the most effective Antibiotic against anaerobic bacteria. Nothing else you took in the past would have addressed that.