Metronidazole belongs to a group of medicines known as anti-microbial agents used to treat bacterial infections of the blood, brain, lung, bone, pelvic area, stomach lining, intestines, gum, teeth, following childbirth or wound infection following an operation. It is also used to treat infected leg ulcers, pressure sores, stomach ulcers caused by Helicobacter pylori, urinary or genital infections caused by Trichomonas parasite, amoebiasis (parasitic infection of the colon), and to prevent infections after surgery.