An anal fissure is a tear in the lining of the anus. It can be acute (<6 weeks) or chronic (>6 week).
Most fissures arise without any underlying disease but can be associated with Crohns disease. They can occur as a result of chronic constipation, passing hard, large stools, repeated episodes of diarrhoea, trauma to the anus or anal canal, childbirth, or reduced blood flow to the anorectal area.
Anal fissures usually cause severe anal pain and bright red bleeding on defaecation. As a fissure becomes chronic, a perianal lump may be felt. Constipation is common but not always present.
This is usually made from the classic history and by simple inspection of the perianal area
Acute Anal Fissure
These heal with simple measure such as stool softeners eg movicol and dietary modifications (increasing fibre). Rectogesic (0.2% GTN) can help to ease symptoms and heal the fissure. Simple hygiene measures such as baby wipes are used to keep the area clean
Chronic Anal Fissure
These fissures are unlikely to heal with conservative measures alone although they should be continued. All treatment options involve measures to relieve anal sphincter spasm in order to allow healing. Options of treatment include:
In a small amount of cases, a fissure persists or recurs despite the above treatment. In such cases it is important to exclude other diseases such as Crohns. Usually an endoanal ultrasound is performed and anal pressures are measured. Options include further botox, a repeat lateral sphincterotomy or an anal advancement flap.