Anal fissures

About anal fissures

An anal fissure is a split in the skin at the opening of the anus, leaving exposed some of the muscle fibres of the anal canal. Pain results from recurrent opening of the wound when the bowels are open and this is often accompanied by bleeding. In addition, the inner circle of muscle in the anal canal (called the internal sphincter) goes into spasm; this makes the pain worse and can prevent healing. Anal fissures are different from haemorrhoids (piles) and have no relationship with cancer.

Symptoms

• Pain on defecation (emptying the bowel) – this may persist for minutes or hours afterwards; the pain is typically sharp and knife-like rather than an ache.
• Bright red bleeding with defecation.
• A skin tag (a piece of skin which hangs from surrounding skin) at the site of the fissure can develop if the fissure is long-standing.

What are the treatments?

General measures

The aim of treatment is to relax the spasm in the internal sphincter (muscle at the upper end of the anal canal). This improves the blood supply to the fissure and prompts healing for most patients.

Keep stools soft and avoid constipation

Eating a high fibre diet and drinking plenty of water (six to ten glasses a day) should help keep your motions soft. A fibre supplement such as Fybogel may help, and laxatives may help to avoid constipation.

Sitz baths

A 15 minute bath in water as warm as you can tolerate several times daily (or as often as you require) can be very soothing and can provide several hours of pain relief.

Glyceryl trinitrate (GTN) and diltiazem ointments

GTN and diltiazem are locally applied ointments which relax the internal sphincter. Although neither is licensed for use in treatment of fissures they are widely accepted by colorectal surgeons to be a valuable alternative to surgery. Both are applied to the outside of the anus by a gloved hand twice a day.

GTN can have a side effect of headaches, whereas diltiazem sometimes makes the skin around the anus sensitive and sore. If either of these side effects occur it is possible to try the alternative ointment. These ointments can be used for several weeks, and if there has been no significant improvement then it is advisable to try the alternative ointment and trial for a few more weeks.

Surgery

Examination under anaesthesia and injection of Botox

The injection of botulinum toxin (Botox) has been shown to relax the internal sphincter. The patient is examined under general anaesthesia and the Botox in injected into the anal muscle area. Botox is effective but may result in a transient and reversible difficulty with the control of gas and possibly liquid stool from the back passage. The principle advantage of Botox is that it is a one-off treatment which lasts for three months, during which the fissure should heal. This treatment may be repeated if needed.

Lateral sphincterotomy

The operation for anal fissure is called an internal sphincterotomy. This means that part of the internal sphincter muscle is cut. The cut relieves the spasm of the muscle, stops the pain and allows the fissure to heal. It is not usually necessary to remove or suture (stitch) the fissure itself. The operation is very effective but carries a risk (10% to 20%) of some change in your ability to control wind or stool from the back passage. For this reason, sphincterotomy is considered the last resort option if all above treatments fail.

Your consultant will explain these options and, with you, decide on which is best for your individual situation.