Definition An anal fissure is a tear in the internal lining of the anus. This area is called the anal mucosa. This break in the anal lining often re-opens during bowel movements. The result is bright red blood and intense pain.
What is going on in the body? An anal fissure is a tear in the bowel lining. It causes painful, bloody bowel movements. It is often confused with haemorrhoids, which are painful swellings at the anus caused by enlarged veins. A fissure can be acute or chronic. The chronic condition is often associated with a buildup of tissue at the external end of the tear. This is called a sentinel pile and may be noticed by an affected person. The internal end may also have a buildup of tissue that an affected person can rarely see.
When a fissure is present, the mucosa of the anus opens each time it is stretched to allow for a bowel movement. This continual opening prevents healing. It can also leave scar tissue. Most chronic fissures are in the centre of the back of the anus, but it may be in the midline anteriorly.
The anal sphincter muscles need to relax for a person to have a bowel movement. A person with a fissure may have muscles that are too tight due to reflex muscle spasm. This makes bowel movements painful, and often associated with bleeding.
What are the signs and symptoms of the condition? The most common symptoms are pain during and after a bowel movement. Often the person will notice bright red blood on the toilet tissue or blood dripping into the toilet after a bowel movement. Because bowel movements are painful, many people complain of constipation.
What are the causes and risks of the condition? Anal fissures are usually related to abnormal bowel movements. Constipation or frequent stools can cause straining and worsen the problem. Injury to the anal area can also damage the anal mucosa. Pregnancy or difficult delivery is often a cause of this trauma. There are also several medical conditions that can cause anal fissures, including:
Venereal warts, which are sexually transmitted warts caused by a virus, can look like anal fissures and may have similar symptoms.
What can be done to prevent the condition? Usually, anal fissures can be prevented by maintaining regularly formed or soft bowel movements. High fibre diets and stool softeners, such as coloxyl, (docusate) are often beneficial.
How is the condition diagnosed? Anal fissures are diagnosed by physical examination and proctoscopy. A proctoscopy allows the doctor to inspect the anal canal using a special device that opens the anus. Sometimes proctoscopy and sigmoidoscopy have to be postponed until local pain and spasm settle.
What are the long-term effects of the condition? Untreated anal fissures can lead to anal fistulas, which are abnormal connections between the anus and another organ, usually a different part of the bowel or the perianal skin. They can also cause anal stenosis, or an abnormal narrowing of the anal canal.
What are the risks to others? Most of the time, anal fissures are not contagious. Rare exceptions occur if the condition is caused by an infection.
What are the treatments for the condition? Treatment of an anal fissure depends on how long the fissure has been present. Acute or relatively new fissures can usually be managed with a bulk-forming laxative, such as psyllium or senna, and a local anaesthetic cream.
These measures may help chronic fissures, but more intensive treatment is usually necessary. Nitroglycerin cream may be useful, and steroid suppositories e.g. proctosedyl inserted at night. However, a surgical treatment called a lateral internal sphincterotomy may be needed. This procedure divides the most superficial fibres of the two anal muscles and corrects any problems. It also allows easier passage of stool through the anal canal. The operation can be done using a local or regional anaesthetic but is usually performed under general anaesthetic.
Acute fissures which do not respond to local measures can often be cured by anal dilation under general anaesthetic.
What are the side effects of the treatments? Once the condition is corrected, there are few side effects to anal fissures. However, a person is at risk of developing another fissure if he or she does not make diet or lifestyle changes. Any surgery involves the risks of anaesthesia, infection, and bleeding.
What happens after treatment for the condition? An individual needs to eat a high fibre diet, maintain regular eating habits, and drink plenty of fluids each day.
Author: Michael Peetz, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
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