An anal fissure is a disruption of the skin at the distal anal canal.
Most fissures are seen by separating the buttocks with opposing traction of the thumbs.
Majority of fissures are located in the posterior midline of the anus.
Acute fissures are simple splits or cracks in the anoderm while chronic fissures may show secondary changes eg sentinel tag, hypertrophied anal papilla, rolled edges, fibrosis of the edges or deep ulceration with exposure of the underlying internal sphincter muscle.
Anal fissure is an ulceration of the anoderm in the anal canal. Treatments usually do not target these causative factors. Recently, this review has been published giving an update on the management of anal fissure.