It's quite difficult for our bodies to overcome pathogens such as the bacteria and parasites that cause food poisoning. Some of those are Salmonella, Shigella, Listeria, certain types of E. coli and protozoa like giardia. Did any of the doctors you saw ever ask you if you had gone camping or traveled outside the country? If they didn't, then should have, especially if you are having GI symptoms. Are they aware you were in Jamaica? http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-4-select-destinations/jamaica "Travelers’ diarrhea is one of the most common travel-related illnesses, and Jamaica has attack rates of 8%–20%." Any doctor can diagnose traveler's diarrhea, medical or naturopath. Either one can write a prescription for antibiotics or anti-protozoa meds. The naturopath is most likely to be the one most helpful in keeping GI distress down while you take any antibiotics. After you finish a round of antibiotics you can re-establish good gut bacteria by taking probiotics. Again, a naturopath will excel at this, or you can take some chances and research probiotics here or on the rest of the Internet. I'm not saying you have a GI infection, but it would be best to have it ruled out before you go on to any other protocols. It's hard to help a body that is fighting a pathogen. Pathogens should be eliminated first, if at all possible. (Pathogen = bad bacteria or protozoa.) The bugs that normally inhabit us aren't a big concern. Commensalism is a relationship between two organisms where one organism benefits without affecting the other. Mutualism is a relationship between two organisms where both organisms benefit. Our gastrointestinal system is a mutualistic system. The bacteria get a place to live and the bacteria help process our food and produce chemicals that are beneficial to us.