Anal Fissure

Question 1

What is an anal fissure.

Answer 1

It is a tear in the sensitive skin-lined lower anal canal distal to the dentate line which produces pain on defecation.
Caused by traumatic or ischaemic damage to the anal mucosa.

Question 2

Where do the majority of anal fissures occur.

Answer 2

In the posterior midline.

Question 3

What is associated with an anal fissure.

Answer 3

Hypertonicity of the internal sphincter.

Question 4

What is the cause of anal fissures.

Answer 4

It is thought to be secondary to passage of a hard stool.

Question 5

What are the symptoms of anal fissures (4)

Answer 5

Severe pain during and after bowel movements.
Bright red PR bleeding.
Mucus discharge.
Pruritus.

Question 6

Who gets anal fissures.

Answer 6

It can be an isolated incident in young to middle aged adults, due to the passage of hard stools.
It can occur in association with Crohn’s disease or Ulcerative Colitis.

Question 7

What are the signs of an anal fissure. (2)

Answer 7

The fissure itself.

There may be a sentinel pile (skin tag at the external aspect of the fissure)

Question 8

How is diagnosis of an anal fissure usually made.

Answer 8

Usually from the history alone, as a rectal exam is usually not possible due to the pain and sphincter spasms.

Question 9

What problems do the sphincter spasms cause. (2)

Answer 9

Cause pain.

Impair wound healing.

Question 10

What is the treatment for anal fissures.

Answer 10

Conservative: dietary fibre and stool softeners.
Medical: local anaesthetic gel (eg lidocaine), GTN cream (relaxes the internal sphincter), dialtiazem ointments.
For chronic fissures botulinum toxin is used.
Surgical: This is usually only in severe cases - a lateral subcutaneous internal sphincterotomy.

Question 11

What are some complications of anal fissures. (4)

Answer 11

If the fissure occurs off the midline, or there is a suspicious history, there many be an underlying pathology for the fissure. 
These include:
AIDS.
Crohn's.
Carcinoma.