The word 'fissure' in a medical sense means a 'tear', and an anal fissure is a tear in the anal lining.
Anal fissures are often caused either by hard stools (typically after a bout of constipation) or by very loose stools over a period of time. When the anal lining tears it causes severe pain and is often accompanied by bleeding from the rectum. It's not unusual for a swollen skin tag to form on the exterior of the anus where a fissure has developed.
Fissures often heal without any medical intervention, however those that don't will need medical treatment.
If a spasm of the internal anal sphincter muscle develops, this cause reduced bloodflow to the site of the fissure and can lead to it not healing and becoming 'chronic'.
Treatment takes one of two forms...
- Anal BOTOX® Injection - a single injection to the anal sphincter. This treatment has very good long-term outcomes and involves minimal complications.
- Sphincterotomy - this surgical procedure reduces anal pressure and stops blood flow to the fissure from being reduced, which allows the fissure to heal naturally. The procedure - called a 'lateral internal sphincterotomy' involves a very small cut (a few millimetres) to the lower internal anal sphincter muscle. It is usually only carried out where non-surgical treatments have been unsuccessful.