Thank you for your kind words, Redgreen. I wouldn't get too caught up in thinking that you have a hidden infection somewhere- I mean, everyone has latent viruses and such, it's just a matter of our immune systems handling them.
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.