Anal Fissure

Question 1

What is an anal fissure?

Answer 1

Painful tear in squamous lining of lower anal canal (chronic is >6wks)
Characterised by pain on defecation + rectal bleeding

Question 2

Describe the distribution of anal fissures

Answer 2

90% = posterior

Anterior anal fissures tend to occur after childbirth

Question 3

Describe the epidemiology of anal fissures

Answer 3

10% lifetime prevalence
M = F
Can occur at any age
Most cases occur in children + YA’s: 10-30 yrs

Question 4

Describe the aetiology of anal fissures

Answer 4

Most caused by hard faeces
Anal sphincter spasm can constrict the inferior rectal artery, causing ischaemia + impairing the healing process
Rare causes: syphilis, herpes, trauma, Crohn’s, anal cancer, psoriasis

Question 5

List 3 risk factors for anal fissures

Answer 5

Hard stools
Pregnancy (esp. 3rd trimester)
Opiate analgesia: associated with constipation + thus increased incidence of anal fissures

Question 6

Describe the nature of symptoms of anal fissures

Answer 6

Symptoms are intermittent

Question 7

List 4 symptoms of anal fissures

Answer 7

Tearing pain when passing stools
Blood in pan/ on paper (blood on top: NOT mixed in with faeces)
Anal itching
Anal spasm

Question 8

Give 2 signs of anal fissures

Answer 8

Tears in the squamous lining of the anus OE

Sentinel piles may be seen (common harmless growths that hang off skin around anus)

Question 9

List 3 conservative management approaches to anal fissures

Answer 9

High-fibre diet
Softening the stools (laxatives)
Good hydration

Question 10

List 4 medical management approaches to anal fissures

Answer 10

Topical analgesic  
Lidocaine ointment (LA) 
GTN ointment (relaxes anal sphincter + promotes healing)  
Diltiazem (relaxes anal sphincter + promotes healing): if the pt gets headaches from GTN ointment

Question 11

Describe the management for resistant anal fissures

Answer 11

1. Botulinum toxin injection – esp. in F where there is concern over the integrity of sphincters after childbirth
2. Lateral partial internal sphincterotomy
   Relaxes anal sphincter + promotes healing but has complications (e.g. anal incontinence) esp. in F who have shorter + weaker sphincters e.g. childbirth injuries so it is reserved for pts who are intolerant or not responsive to non-surgical tx

Question 12

Give 2 complications of anal fissures

Answer 12

Chronic anal fissure – if left untreated

Incontinence AFTER SURGERY

Question 13

What is the prognosis of anal fissures?

Answer 13

In most: fissure will heal within ~ 1 week

Tx aims to ease pain by keeping the stools soft + relaxing the anal sphincter to promote healing

Question 14

Describe the diagnosis and investigation of anal fissures

Answer 14

Clinical dx
If anal sphincter deficits suspected; may do anal US to examine the internal + external sphincter
DRE NOT conducted in suspected anal fissures due to immense pain

Question 15

What is the pain caused by anal fissures compared to?

Answer 15

“passing broken glass”