Anal Fissure

This is an extremely painful anal condition. A fissure is a linear break/tear of the lining of the anal mucosa. The most common position where this occurs is in the posterior midline (80%). Second most common location is anterior midline (20%).  Often patients with fissures described sharp, stabbing pain in the anus that is made worse when opening their bowels. Sometimes, they may also notice a small volume of fresh blood on the toilet paper when wiping.


The main cause of anal fissures is trauma to the anal lining. This usually occurs with constipation when a hard and large stool is passed, resulting in a tear of the anal lining.

Other rare causes include medical conditions (such as inflammatory bowel disease), medications, infections and cancer.


Treatment involves keeping the stool soft. A high fibre diet with increased fluid intake is desirable. This may be the only treatment necessary for superficial acute fissure.

Medical treatment in the form of creams/ointments which reduce the spasm of the anal sphincter muscle to allow healing is the most commonly prescribed treatment. The most readily available ointment is RectogesicTm. This is applied directly on the fissure. The treatment duration is at least 3-4 weeks before improvement is felt. The success rate is about 50-60%.

Major side effect: Headaches

Botox injection
This is the same injection that is widely used in cosmetic surgery. The toxin is injected directly into the anal sphincter muscle to cause temporary partial paralysis of the sphincter muscles and allow healing to occur. Generally, this will require hospital admission and minor anaesthesia. This treatment is not readily available due to the cost. Success rate is around 60-70%.

Major side effect: Allergic reaction (very rare)

This is the most effective treatment for anal fissures. The success rate is around 80-95%. The procedure involves dividing a small portion of the sphincter muscle. Hospital admission with anaesthesia is required. When carried out properly by a specialist surgeon in suitable patients, the long-term side effects of this procedure is negligible.

Major side effect: Flatus incontinence