An anal fissure is a narrow tear that extends from the muscles that control the anus (anal sphincter) up into the anal canal. These tears usually develop when anal tissue is damaged during a hard bowel movement or when higher-than-normal tension develops in the anal sphincters.
About 9 out of 10 short-term fissures heal with home treatment-including using stool softeners or fiber supplements and taking regular sitz baths. And about 4 out of 10 long-term anal fissures will heal after home treatment is used.
But not all fissures will heal with just home treatment. If a fissure lasts more than 8 to 12 weeks, you may need prescription medicines. These may include nitroglycerin cream, high blood pressure medicines in pill or gel form, or injections of botulinum toxin (Botox).