Anal Fissure

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Anal Fissure


Fissure is a tear in the anal canal extending from just below the dentate line to the anal verge. This is most commonly in young and middle age adults.The cardinal symptom is pain during and for minutes to hours following defecation.Bright red blood formation is common in Anal fissures. Over 90% of anal fissures are located in the posterior midline and rest located in the anterior midline. Distal sentinel tag, a proximal hypertrophied anal papilla, fibrotic edges, and exposed internal sphincter fibres are features of chronicity. In the acute fissure it is a formation "mere crack" in the anoderm.


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


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