An anal fissure, the most common cause of anal pain, is a small cut or tear in the lining of the anal canal. While common, fissures are often confused with other causes of pain and bleeding, such as hemorrhoids.
Symptoms of an anal fissure are pain and/or bleeding after a bowel movement. Pain may be so intense as to cause severe constipation from avoidance of having a bowel movement.
Anal fissures are cause by trauma, i.e., anything that can cut or irritate the inner lining of the anus—most typically, a hard, dry bowel movement—or diarrhea or anal inflammation. Anal fissures may be acute (recent onset) or chronic (present for a long time or recurring frequently). Chronic fissures often have a small lump known as a sentinel pile or skin tag.
Treating constipation or diarrhea can oftentimes allow for healing a fissure. An acute fissure is typically managed conservatively, with over 90% healing without surgery. Conservative management of fissures includes maintaining a high fiber diet; bulking agents, stool softeners, and extra fluid intake will also help soften bowel movements, relieve constipation and allowing for healing. (Increased dietary fiber may also help to improve diarrhea.) Warm baths for 10-20 minutes relax and clean the area, promoting healing.
Occasionally, a topical muscle-relaxing cream is prescribed to relax the sphincter muscles. Botox injections are also a treatment option for stopping spasms and pain.
Patients need to continue good bowel habits, including following a high fiber diet, after a fissure has healed because fissures can recur easily. If fissures recur without explanation, or fail to respond to treatment, further assessment may be warranted. Other medical problems can cause symptoms similar to fissures and need to be ruled out in cases of persistent anal pain.
Surgery is a very effective treatment for a fissure and recurrence rates after surgery are low. Surgery usually consists of a small outpatient operation to cut a portion of the internal anal sphincter muscle (a lateral internal sphincterotomy). If a skin tag is present, it too may be removed to promote healing of the fissure. A sphincterotomy rarely interferes with bowel movement control. Surgery does have other risks, and your surgeon will address these with you. After surgery, complete healing occurs in a few weeks, although pain often disappears after a few days.
Fissures do not lead to colon cancer. Persistent symptoms, however, need evaluation since other conditions cause similar symptoms. Even if your fissure has healed, your doctor may want to perform additional testing, including colonoscopy, to exclude other causes of bleeding.