An anal fissure is a tear or open sore (ulcer) that develops in the lining of the large intestine, near the anus.
An anal fissure is a small tear in the lining of your bottom (anus).
Symptoms of an anal fissure include a sharp pain and bleeding when you poo.
Anal fissures are usually caused by constipation. Other causes include long-lasting diarrhoea, inflammatory bowel disease, pregnancy and childbirth.
An anal fissure usually heals on its own. Treatment includes avoiding constipation, and medicines to reduce pain and speed up healing.
Page last reviewed: 23/11/2018
Next review due: 23/11/2021