Chronic anal fissure: 0.2% topical glyceryl trinitrate ointment

What is chronic anal fissure?

An anal fissure is a common and often painful problem caused by a small tear or ulcer (open sore) in the lining of the anus (back passage). This can cause bleeding, local itching and pain with a bowel movement, which can be severe. When someone has an anal fissure the first treatments can include a high-fibre diet, laxatives and applying anaesthetic ointments to the affected area. Anal fissures usually heal within a few weeks but those that have not healed after 4–6 weeks are called chronic fissures.

If someone has a chronic fissure, it is thought that the reason it has not healed is that the ring muscle (sphincter) that goes around the anus (back passage) has become so tense that the flow of blood to the lining of the anus is reduced. That means that not enough oxygen (carried by the blood) gets to the fissure (or tear). Without enough oxygen, the cells which make up the lining can't grow and repair (heal) the fissure (or tear).

A licensed medicine for treating chronic anal fissure in adults (over 18 years of age) is available in the UK. This is a 0.4% glyceryl trinitrate ointment (also called Rectogesic 4 mg/g Rectal Ointment), and is usually tried for a period of 8 weeks (see about glyceryl trinitrate for more information). If the person has had to stop treatment with 0.4% glyceryl trinitrate or it hasn't worked, there are other treatments that aren't licensed in the UK which may be tried. These unlicensed treatments include a 0.2% strength of glyceryl trinitrate ointment, diltiazem cream or ointment (see NICE's evidence summary on 2% topical diltiazem hydrochloride for chronic anal fissure for more information), or botulinum toxin injections (such as Botox or other brands) into the area around the anus (back passage). A surgical procedure called sphincterotomy may also be tried.