The digestive system terminates in the anus, the opening of the rectum to the outside of the body. Bounded by a strong circular ring of muscle called the anal sphincter, the anus opens and closes to control defecation. An anal fissure occurs when the delicate skin around the anus tears, creating a painful, bleeding crack. Most anal fissures occur on the midline of the posterior, or back part, of the anus.
Symptoms
Anal fissures cause pain or a burning sensation in the skin around the anus, especially during and after defecation. The pain might last for up to several hours, and then resolve until the next bowel movement. The American Gastroenterology Association states that the pain can be so severe that some people suffering from anal fissures try to avoid bowel movements altogether. After defecation or while healing, the torn area might itch or be red and irritated. The torn skin often bleeds, resulting in bloody stools or blood on the toilet paper when wiping after defecating. Because the blood is fresh, bleeding due to an anal fissure is bright red. In addition to these signs, a doctor's exam will uncover tears in the skin around the anus.
Causes
Anal fissures most often result from damage to the delicate skin around the anus from the passage of large or very hard stools. Straining during a bowel movement can tear the anus as well. Anal fissures occur more commonly in babies, senior citizens and women who have given birth.
Significance
Though painful, simple acute anal fissures are not serious. They usually heal on their own with time. According to the American Gastroenterology Association, if an anal fissure occurs off the midline of the anus, doctors should suspect more serious causes such as Crohn's disease, tuberculosis or anal cancer.
Healing
An anal fissure usually heals without medical intervention. According to the Mayo Clinic, within two weeks or so of the original injury, the tear heals enough that the pain and bleeding stop. If necessary, a doctor might prescribe protective ointments or botulinum toxin injections to relax the anal sphincter and allow healing. If the tear does not heal completely within six to eight weeks, surgery might be necessary. During healing, it is important to avoid constipation or straining which could re-open the tear.
Types
While acute anal fissures heal on their own within a few weeks, chronic fissures fail to heal after a few months. Chronic fissures look different from acute anal fissures, according to the American Gastroenterology Association: the skin around them thickens, and they might have a skin tag or small bump at either end of the tear. Chronic fissures are more difficult to treat.
