An anal fissure is a tear in the anal canal, most commonly located in the posterior midline. It causes pain during and after defecation and sometimes bleeding. The tear is usually caused by hard stool stretching the anal lining. Acute fissures may heal with increased fiber and warm baths in 3 weeks, but chronic fissures require additional treatment like topical nitroglycerin or calcium channel blockers to relax the internal sphincter and increase blood flow, or a lateral internal sphincterotomy surgery which achieves over 95% healing. Recurrence is common without lifestyle changes to prevent hard stools.

1. ANAL FISSUREANAL FISSURE

2. INTRODUCTIONINTRODUCTION
 Fissure is a tear in the anal canal extending fromFissure is a tear in the anal canal extending from
just below the dentate line to the anal verge.just below the dentate line to the anal verge.
 Most commonly in young and middle age adults.Most commonly in young and middle age adults.
 The cardinal symptom is pain during and forThe cardinal symptom is pain during and for
minutes to hours following defecation.minutes to hours following defecation.
 Bright red blood is commonBright red blood is common

4. INTRODUCTIONINTRODUCTION
 Over 90% of anal fissures are located in theOver 90% of anal fissures are located in the
posterior midline.posterior midline.
 Almost all the rest located in the anterior midline.Almost all the rest located in the anterior midline.
 The acute fissure is a "mere crack" in theThe acute fissure is a "mere crack" in the
anoderm.anoderm.
 Distal sentinel tag, a proximal hypertrophied analDistal sentinel tag, a proximal hypertrophied anal
papilla, fibrotic edges, and exposed internalpapilla, fibrotic edges, and exposed internal
sphincter fibres are features of chronicitysphincter fibres are features of chronicity

5. Etiology and PathogenesisEtiology and Pathogenesis
 The initiating factor is trauma, typically overstretching of theThe initiating factor is trauma, typically overstretching of the
anoderm by a large hard stool.anoderm by a large hard stool.
 The proposed explanation for the posterior midlineThe proposed explanation for the posterior midline
predominance is a lack of tissue support and maximalpredominance is a lack of tissue support and maximal
stretching at this site.stretching at this site.
 Failure to heal is secondary to poor perfusion of theFailure to heal is secondary to poor perfusion of the
anoderm in the posterior midline.anoderm in the posterior midline.
 Posterior midline ischaemia is the result of arterial anatomyPosterior midline ischaemia is the result of arterial anatomy
and internal anal sphincter hypertonicity.and internal anal sphincter hypertonicity.

6. TreatmentTreatment
 Warm baths and a diet sufficiently high in fibre toWarm baths and a diet sufficiently high in fibre to
achieve soft bulky stools allows approximatelyachieve soft bulky stools allows approximately
50% of acute anal fissures to heal within three50% of acute anal fissures to heal within three
weeks.weeks.
 Stool softeners and fibre supplements areStool softeners and fibre supplements are
reasonable additions.reasonable additions.
 Recurrence is common, in the range of 30 - 70%,Recurrence is common, in the range of 30 - 70%,
but can be reduced to 15 - 20% by maintaining abut can be reduced to 15 - 20% by maintaining a
high fibre diethigh fibre diet

7. Acute FissureAcute Fissure
Topical ApplicationTopical Application
 Nitric oxide has been identified as the chemical messengerNitric oxide has been identified as the chemical messenger
of the intrinsic non-adrenergic, non-cholinergic pathwayof the intrinsic non-adrenergic, non-cholinergic pathway
mediating relaxation of the internal anal sphincter.mediating relaxation of the internal anal sphincter.
 Topical application of nitroglycerin, a nitric oxide donor,Topical application of nitroglycerin, a nitric oxide donor,
causes a transient lowering of resting anal pressure and ancauses a transient lowering of resting anal pressure and an
increase in anodermal blood flow.increase in anodermal blood flow.
 A 92% healing rate within two weeks for acute fissuresA 92% healing rate within two weeks for acute fissures
treated with application of 0.2% glyceryl trinitrate ointmenttreated with application of 0.2% glyceryl trinitrate ointment
t.i.d.t.i.d.

8. Acute FissureAcute Fissure
Topical ApplicationTopical Application
 Topical calcium channel blockers (2%Topical calcium channel blockers (2%
diltiazem, 0.3% nifedipine) .diltiazem, 0.3% nifedipine) .
 Heal 65-95% of fissures .Heal 65-95% of fissures .
 The most common side effects areThe most common side effects are
headache, flushing, and symptomaticheadache, flushing, and symptomatic
hypotension.hypotension.

9. TreatmentTreatment
Chronic FissureChronic Fissure
 Topical Nitroglycerin: At eight weeks healingTopical Nitroglycerin: At eight weeks healing
was observed in 68% of the GTNwas observed in 68% of the GTN
 Botulinum Toxin: Botulinum toxin has beenBotulinum Toxin: Botulinum toxin has been
injected into the external and internalinjected into the external and internal
sphincters and, with short term follow up,sphincters and, with short term follow up,
healing rates of 80% have been achieved.healing rates of 80% have been achieved.

10. TreatmentTreatment
Chronic FissureChronic Fissure
 Are unlikely to heal with warm baths and aAre unlikely to heal with warm baths and a
high fibre diet.high fibre diet.
 Internal Sphincterotomy : Lateral internalInternal Sphincterotomy : Lateral internal
sphincterotomy (LIS) achieves healing insphincterotomy (LIS) achieves healing in
over 95% within several weeksover 95% within several weeks
 Anal DilatationAnal Dilatation