I only got a "PPTU" because I tested myself and have limited microbiological experience. Beforehand, I have been tested by a medical lab and found to have D. Fragilis. Then I had treatment with paromomycin. After which, I was in the middle of trying a Hulda Clark -type herbal treatment when my doctor decided to test me again. The test came back negative, although I knew I was still sick. I then did a ton of research and obtained all of the supplies necessary to test myself. That's when I found that there were still (many) D. Fragilis trophozoites inside me. But D. Fragilis is easy to indentify. it has two nuclei, and is within a certain size range. B. Homonis and others can sometimes be more tricky. HOPEFULLY, I'll have time to retest myself this weekend. I dunno. I've been strapped so far.