Anal Fissure

Question 1

What are anal fissures?

Answer 1

A painful tear in the squamous lining of the lower anal canal
- NOTE: 90% of anal fissures are posterior (anterior anal fissures tend to occur after childbirth)

Question 2

What are the 2 types of anal fissures a patient may have?

Answer 2

1. Primary (Due to local Trauma) → low fibre intake, chronic constipation or diarrhoea, anal sex
2. Secondary (Due to Underlying Disease) → previous anal surgery, IBD, infections, malignancy

Question 3

What are the causes/ risk factors for anal fissure?

Answer 3

Most are caused by hard faeces
Anal sphincter spasm can constrict the inferior rectal artery, causing ischaemia and impairing the healing process

RF’s:
- hard stool/constipation (can tear skin in distal anal canal)
- pregnancy (may occur in 3rd trimester or after delivery)
- opiates (associated with constipation)

Question 4

Summarise the epidemiology of anal fissures

Answer 4

Affects 1/10 people during their life time
Both sexes are affected equally
Can occur at any age
Most cases occur in children and young adults: 10-30 yrs

Question 5

What are the presenting symptoms of an anal fissure?

Answer 5

• Tearing pain when passing stools
• Pain on defecation
• There may be a little bit of blood in the faeces or on the paper
• Anal itching (pruritus ani)
• Anal spasm

Question 6

What signs of anal fissure can be found on physical examination?

Answer 6

Tears in the squamous lining of the anus on examination

Question 7

What investigations are used to diagnose/ monitor anal fissure?

Answer 7

1. Usually a clinical diagnosis (examining the anus) and no tests are necessary at initial presentation
2. May do Anal Manometry or Anal Ultrasound

Question 8

How are anal fissure’s managed?

Answer 8

1. Acute Anal Fissure (<1 week)
   a. Conservative → manage constipation (bulk-forming laxatives - stool softners), high fibre diet, adequate fluid intake, application of lubricant prior to defecation (petroleum jelly), sitz baths
2. Chronic Anal Fissure (>6 weeks)
   - Analgesia → topical GTN (glyceryl trinitrate) or topical diltiazem
   - Persistent Fissures (GTN not effective after 8wks = refer to surgery) → botulinum toxin injection/surgical sphincterotomy (spincter is cut/ stretched to reduce pressure inside the anus that can cause spasms and increases blood flow to the area to help the tissue heal.)

Question 9

What complications may arise from an anal fissure?

Answer 9

Chronic anal fissure, incontinence after surgery, recurrence 

Question 10

Summarise the prognosis for patients with anal fissure

Answer 10

• In most people, the fissure will heal within a week or so
• Treatment revolves around easing pain by keeping the stools soft and relaxing the anal sphincter to promote healing