There can be a number of pathogens (protozoa, bacteria, yeast etc) that could be the issue. d. fragilis is just one of a myriad of protozoa that can infect. Each protozoa infection requires a different protocol, so it would be best not to guess at what you have. The best procedure is to do a test thru Metametrix GI Effects - don't waste your time with other labs, not worth it.