Anal Fissure Flashcards
Define anal fissure
Split in the skin of the distal anal canal*, characterised by pain on defecation and rectal bleeding
*Anal canal - large bowel between rectum and anus
Acute: split in the skin of the distal anal canal (<1-2 weeks)
Chronic: Fissure persisting for >6 weeks, often shows features such as indurated edges, a skin tag and visible internal anal sphincter fibres
Aetiology and risk factors of anal fissures
Passage of a hard stool bolus (constipation, opioid use)
May occur spontaneously without any precipitating factors
Pregnancy
Opiate analgesia
Symptoms of anal fissure
Pain on defecation
- 10/10
- “like passing sharp glass”
Tearing sensation on passing stool, followed by burning pain for several hours
Fresh blood on stool or paper
Anal spasm
Sentinel pile (skin tag) - external lump
Fissure visible on retraction of buttock
Investigations for anal fissures
Clinical Diagnosis - too painful to do DRE
For patients with resistant fissures:
Anal manometry: ?treatment for resistant fissures
Anal US: ?defect in anal sphincters
Management for anal sphincters
- Conservative:
- High fibre diet
- Adequate fluid intake
- Sitz baths
- Topical analgesia
- Stool softeners
- Lubricants (petroleum jelly) - Bulk-forming laxatives
- Adjunct (chronic, >6 weeks):
- topical GTN (S/E headache)
- topical diltiazem (CCB) if GTN intolerable
Resistant:
Botulinum toxin injection to relax the anal sphincter
Surgical sphincterotomy to remove the internal anal sphincter and reduce spasm (risk of faecal leakage and incontinence)
Anal advancement flap (lower risk of incontinence)
Prognosis for anal fissures
Most anal fissures are shallow and will heal spontaneously within a few weeks. Deep fissures have poorer healing as the sphincter spasm impairs anal blood supply.
60% of fissures will heal by 6-8 weeks
20% heal after topic diltiazem
20% require surgery
