Anal fissure is one of the conditions that most affects quality of life. The intense pain during and after defecation — which can last for hours — leads many patients to avoid going to the toilet, which worsens the problem and allows the lesion to become chronic.
What is an anal fissure?
An anal fissure is a small tear or ulcer in the lining of the anal canal. Although it is a small lesion, it causes disproportionate pain due to the high concentration of nerve endings and the spasm of the internal anal sphincter.
There is the acute fissure (fewer than 6 weeks) and the chronic fissure (more than 6 weeks), which is the one that usually requires specialist treatment.
Why does it hurt so much?
The pain follows a self-reinforcing cycle: the tear causes pain → pain generates sphincter spasm → spasm reduces blood supply → ischaemia prevents healing → the fissure does not heal.
Symptoms
- Intense pain during defecation that can last minutes or hours
- Scant bright red bleeding
- Itching or burning in the anal area
- Sentinel tag in chronic fissures (a small lump at the edge)
Treatment without surgery: botulinum toxin
The injection of botulinum toxin into the internal anal sphincter is an excellent alternative to surgery for chronic anal fissure. It temporarily relaxes the muscle, eliminating the spasm and allowing the fissure to heal naturally.
- Performed at the clinic, in the same appointment as the diagnosis
- No general anaesthesia or hospital admission
- Immediate recovery
- Success rate of up to 70%
- No risk of incontinence, unlike conventional surgery
Prevention
A fibre-rich diet, adequate hydration, avoiding constipation, and seeking advice early at the first symptoms — before the fissure becomes chronic — are the key preventive measures.