Introduction 

Fissure in ano is a condition where a small elliptical shaped ulcer develops in the lower part of the anal canal. It occurs at the point where the soft internal mucosal lining of the anal canal changes into the external skin of the surrounding perineum.

These are normally found at the most posterior part of the anal canal, although this is not always the case. They are most commonly found in young adults but may occur at any age. The characteristic of Fissure in ano shared by many ulcers, is that typically if healing is delayed, the symptoms without appropriate treatment may become chronic.

What are the symptoms?

• Pain at the anal margin (severe and sharp that may last for some hours after) opening the bowels
• Bleeding (due to injury of the fragile incompletely healed ulcer base) usually bright red in colour present only on the toilet paper
• Mucous Discharge (Seepage from the anal canal through the guttering effect of the ulcer)
• Itching (From mucous and stool that may now soil the skin around the anal canal)
• Anal Skin Tag felt at the skin around the anal margin

Why do they occur?

The precise reason as to why patients get fissure in ano is not known but what is for certain is that the stimulus for development comes from tearing of the mucosal-skin junction at the time of evacuation. This may be commonly as a result of a period of constipation or diarrhoea. Fissure may occur after anal surgical procedures or be associated with other conditions of the anal canal and bowel although this is uncommon.

It is believed that the pain experienced at the time of evacuation through the unhealed area of a fissure results in spasm of the anal sphincter and reduction in blood flow to the injured area. As a result proper healing cannot fully occur. With each bowel movement the condition is further aggravated and a vicious circle of injury, pain, spasm and poor healing occurs.

Treatment?

Depends upon the severity of symptoms and the length of time they have been present. The longer the duration of symptoms the longer and more complex the treatment may become. Most fissure symptoms are experienced transiently and probably heal without any form of intervention very quickly. For those that do not a graded approach to management is used.

The complexity and risk of each treatment increases as a number of chronic non-healing fissures are identified. Happily these are present in only a very small percentage of the patients affected by this common condition.

Conservative measures- work by softening the stool and reducing pain, muscle spasm and swelling:

1. Laxatives
2. Topical local anaesthetic gels
3. Warm baths/ Ice packs
4. Oral pain-killers

Drug Treatments – work by causing anal muscle relaxation and increase blood flow to allow healing:

• Glycerol Trinitrate (GTN/ Rectogesic®) Ointment
• Diltiazem (Anoheal® Ointment)

Surgery-may clean the edges of the fissure, paralyse the sphincter or replace the lining of the anal canal and skin :

• Fissure debridement (surgical scubbing)
• Botox® injection to the ana sphincter (temporary paralysis of the sphincter)
• Advancement flap techniques
• Sphincterotomy (division of part of the anal sphincter) a last resort. skin around the anal margin

What happens next?

With appropriate treatment symptoms should settle completely and no long term modification to lifestyle is usually required other than the avoidance of constipation. This is best achieved by adherence to a high fibre diet.

A specialist should carry out an examination of the anal canal and rectum once symptoms are settled to ensure no other more unusual cause for the development of the fissure are present.

A symptomatic fissure may make this examination in the clinic impossible in which case it is done under a short general anaesthetic by a colorectal surgeon.