I have been living in hong kong for six months (from us). for the last four months, I have been suffering from diarrhea. I took three courses of cipromycin over the course of three months. Each time i finished a course, I would return to normal bowel movements. Then, over the next few weeks the diarrhea would return. When the diarrhea returned fir the fourth time, I had lab work done which showed no parasites or bacteria. A second doctor explained that giardiasis may not show up in stool samples. He had me take tinidazole for fear that I had giardiasis. He gave me a 4 pill single dose which I took last night. This morning I had large volumes of diarrhea that was yellow in color and mostly structured as soft formed coils of stool. I became queasy when I had the diarrhea. Later in the day I noticed smaller amounts of diarrhea that floated. Does this indicate that the drug is working and that I do indeed have giardiasis?