Ornitab 500mg Tabs 10'sOrnitab 500mg contains the active ingredient ornidazole. Ornidazole is used to treat people who have certain types of vaginal, urinary tract and intestinal infections, or some specific infections that are in the body. These infections may be caused by anaerobic bacteria (bacteria that do not use oxygen) or amoeba (single celled parasites). It is also used to guard against the possibility of these types of infections during surgery (prophylaxis).