Anal Fissure

Dear Dr. B: I have painful bowel movements. I also bleed rectally. I thought I have hemorrhoids. But I have been told I have a fissure. What is a fissure? How did I get it? How can I get rid of it?

Many of the patients who are evaluated in the office for hemorrhoidal problems have in fact other conditions. It is important to remember that all anal or rectal symptoms are not due to piles or hemorrhoids.

Anal fissure (fissure-in-ano) is a painful condition. It can be confused with hemorrhoids. Uncomplicated hemorrhoids should not be painful. Hemorrhoids can be a nuisance but not painful unless they are thrombosed (have a blood clot) or are strangulated.

What is a fissure?

Chronic anal fissure is a tear in the lower half of the anal canal. There is a disruption of the skin at the entrance of the anus. The condition was first recognized in 1934. Ninety percent of the fissures are at six o’clock position (posteriorly).

Many patients with chronic fissure develop a sentinel skin tag and a little growth of tissue (hypertrophied anal papilla) inside the anal canal.

How does one get a fissure?

The exact cause of anal fissure is hard to define. Injury due to passage of a large or hard stool is thought to be the common initiating factor. But it is not always possible to get this history from patients who have a fissure. Some get a fissure after a bout of diarrhea.

Patients who have a fissure have a high resting pressure in the anal canal – that means the anal sphincter muscle tone is much higher than those who have no fissure. This high pressure causes reduced blood supply to the sphincter muscle at six o’clock position. Passing hard stool through a sphincter with high muscle tone can cause a tear in the lining of the sphincter.

The tear causes pain and further increases the spasm in the sphincter and perpetuates the problem. Patients are afraid to have a bowel movement. The more they delay the bowel movement the worse it gets as the stool gets drier and harder.

Fissures can occur in patients with Crohn’s disease and HIV/AIDS.

What is the treatment?

Treatment can be medical or surgical.

Medical treatment can heal the fissure in about 50 to 60 percent of patients. The treatment involves:

-Hot bath two to three times a day.
-Use of psyllium fiber supplements (Metamucil or Prodiem) to keep the stool soft and bulky.
-Use of ointment to relax the anal sphincter. This reduces the resting anal pressure and improves blood supply to the sphincter and allows the fissure to heal.

Glyceryl trinitrate ointment has been shown to be effective for anal fissures, but it causes headaches in a significant number of patients.

Newer treatments with fewer expected side effects include diltiazem, nifedipine, and injection of botulinum toxin. Others have tried nitric oxide, anal dilatation and hyperbaric oxygen. None of these treatments provide 100 percent cure rate. Each has advantages and disadvantages.

About 30 percent of patients will have recurrence of fissure after medical therapy.

Surgical treatment is offered to those who do not respond to medical treatment or who have frequent recurrences. The surgery of choice is lateral internal sphincterotomy (division of anal sphincter).

The surgical procedure is associated with minor continence alterations in a minority of patients. Rate of recurrence of fissure after surgery is small – three percent in one series.

How can I prevent getting a fissure in the future?

The quality and quantity of stool passing through the anal sphincter is important. It should be soft, bulky and dry. Chew your food well. Eat fruits and vegetables. Use of psyllium helps. And relax when you have a bowel movement.

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