Anal fissure is a painful ulcer usually occurring in the posterior midline of the skin just outside the entry to the rectum. Its persistence is due to spasm of the internal sphincter muscle. The typical pain of this condition is pain on moving one's bowels that persists for some time afterward. Relief with healing of chronic fissures until very recently has been achieved by surgical procedures aimed at ablation of the sphincter spasm. Because of the risk of incontinence resulting from surgery, medical alternatives for surgery have been sought. Among the older medications, bran is effective in preventing recurrence of acute fissure. Local application of muscle relaxing therapy is effective in healing chronic anal fissure, though not as well as surgery, and with considerable risk of adverse events during therapy. There is a Cochrane review related to this review dealing only with surgical procedures.
Anal fissures often heal within a few weeks if you take steps to keep your stool soft, such as increasing your intake of fiber and fluids. Soaking in warm water for 10 to 20 minutes several times a day, especially after bowel movements, can help relax the sphincter and promote healing.
If your symptoms persist, you'll likely need further treatment.
Externally applied nitroglycerin (Rectiv), to help increase blood flow to the fissure and promote healing and to help relax the anal sphincter. Nitroglycerin is generally considered the medical treatment of choice when other conservative measures fail. Side effects may include headache, which can be severe.
Topical anesthetic creams such as lidocaine hydrochloride (Xylocaine) may be helpful for pain relief.
Botulinum toxin type A (Botox) injection, to paralyze the anal sphincter muscle and relax spasms.
Blood pressure medications, such as oral nifedipine (Procardia) or diltiazem (Cardizem) can help relax the anal sphincter. These medications may be taken by mouth or applied externally and may be used when nitroglycerin is not effective or causes significant side effects.