Metronidazole is an antibiotic mainly used for the treatment of systemic or localized infections caused by anaerobic bacteria, metronidazole anal administration for anal canal inflammation, sinusitis and so on. 1. Anal canal inflammation: an inflammation of the anal canal caused by long-term fecal stimulation and poor defecation habits, which can cause persistent throbbing pain, anal itching, anal swelling and other discomforts. 2. Sinusitis: refers to the acute and chronic inflammation of the anal sinuses and anal valves, which is mainly characterized by incomplete defecation, anal swelling, pain, itching and other discomforts. The above two diseases can be given metronidazole anal administration, metronidazole oral may cause nausea, abdominal pain, diarrhea and other discomforts, rectal administration can avoid causing gastrointestinal adverse reactions can also speed up the rectum to the absorption of the drug, so as to play a role in the rapid. It is contraindicated in pregnant and lactating women. If anal discomfort occurs, it is recommended to consult a doctor in time and follow the doctor’s instructions to use the drug, not self-medication.