Metronidazole is a prescription antibiotic and antiprotozoal medication used to treat infections caused by anaerobic bacteria and parasites. It is commonly prescribed for gastrointestinal infections, gynecological infections, dental infections, liver abscesses, amoebiasis, giardiasis, and certain sexually transmitted infections. Metronidazole works by disrupting DNA synthesis in microorganisms, leading to cell death. It is also widely used for prevention of post-operative anaerobic infections.