An anal fissure is a small break or tear in the anal skin or mucosa. The fissure often runs in the longitudinal direction of the anal cleft, on the front or rear side of the anus. The condition is usually caused by constipation and too hard stools. Anal fissure is a very nasty and painful condition, that many people feel ashamed of.


An anal fissure can have different causes. The condition may occur due to constipation and hard pressure (to get rid of the stool). Constipation is caused by hard, dry stools. There may also be an increased tension (a kind of cramp) in the anal sphincter. Cramp in the anal sphincter results in reduced blood flow into this muscle. This will heal wounds, such as fissures, less well. Wounds and fissures in the anus are also found in chronic inflammatory bowel diseases and particularly in Crohn's disease.


Although an anal fissure is usually small (less than one centimeter), it can be very painful because the anus is very sensitive. It particularly hurts during bowel movement. In addition, the stool might be accompanied by bright red blood loss or blood when wiping off. Sometimes, the pain causes cramping of the anal sphincter. This cramping increases as a result of the pain caused by the fissure. The condition is therefore often chronic.


The diagnosis of anal fissure is usually made based on the symptoms and physical examination by a doctor. The doctor looks at the anus and the area around it and can thus identify a fissure. If necessary, the doctor can examine the inside of the anus and rectum with a finger. This is called a rectal examination. In some cases, more investigation is needed to make the diagnosis. This can be done by means of an exploratory examination of the anus and rectum (proctoscopy or sigmoidoscopy). With this examination through the anus, the doctor can view the inside of the anus and rectum.


In the first instance, the doctor will advise to keep stools soft and supple. Optionally, the doctor can prescribe medicines to soften the stool. Anal fissure may be treated with an ointment. There are various types of ointments available.
Sometimes, botulinum injections around the anus give good results. Botulinum temporarily reduces the increased tension of the anal sphincter. This eliminates the cramps, improves blood circulation and may heal the fissure. The effect of the injection lasts approximately three months. Optionally, the injection can be repeated.
If the symptoms persist, even after prolonged treatment with the above agents, surgery is sometimes performed. This intervention is not done very often anymore and can cause side effects, such as incontinence. The operation method applied is the so-called LIS method (LIS = Lateral internal sphincterotomy). Through a small operation wound next to the anus, the inner part of the anal sphincter is cut at the side. The tension on the fissure decreases then, allowing it to heal.


An anal fissure generally heals within four to six weeks. Treatment and prevention of anal fissures is succesful in 80% of the cases. If an operation is to be performed, the condition will disappear in most cases.