Fissure in ano or anal fissure is a linera tear in the lining of the distal anal canal below the dentate line. It is a common condition affecting all age groups, but it is particularly seen in young and otherwise healthy adults. The incidence is equal in both sexes.<sup>6 Bennett R.C., Goligher J.C. Results of internal sphincterotomy for anal fissure BMJ 1962 ;  2 : 1500  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> The classic symptoms are anal pain during or after defecation accompanied by the passage of bright red blood per anus. The pain often is severe and may last for a few minutes during or persist for several hours after defecation. Bleeding from an anal fissure usually is modest and separate from the stool. Significant loss of fresh blood may be from another source such as hemorrhoids because these two conditions commonly coexist; altered blood or blood mixed with the stool indicates other pathology. Pruritus ani accompanies anal fissures in 50% of cases.<sup>18 Daniel G.L., Longo W.E., Vernava A.M. Pruritus ani: Causes and concerns Dis Colon Rectum 1994 ;  37 : 670-674  [cross-ref]

Haga clic aquí para ir a la sección de Referencias, 76 Mazier W.P. Hemorrhoids, fissures, and pruritus ani Surg Clin North Am 1994 ;  74 : 1277-1292  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> Symptoms from fissures cause considerable morbidity and reduction in quality of life in otherwise generally young healthy individuals.<sup>97 Sailer M., Bussen D., Debus E.S. , y al. Quality of life in patients with benign anorectal disorders Br J Surg 1998 ;  85 : 1716-1719  [cross-ref]

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On examination, the fissure may be apparent as a linear or pear-shaped split in the lining of the distal anal canal as the buttocks are parted, but there often is marked spasm of the anal sphincter that obscures the view. The combination of spasm and intolerable pain often precludes a digital rectal or proctoscopic examination, but a typical history supported by clinical findings of anal spasm makes the diagnosis of anal fissure highly likely. If visualized, an early fissure has sharply demarcated fresh mucosal edges, and there may be granulation tissue in its base. With increasing chronicity, the margins of the fissure become indurated, and there is a distinct lack of granulation tissue. Horizontal fibers of the internal sphincter muscle may be evident in the base of the mucosal defect, and secondary changes, such as a sentinel skin tag, hypertrophied anal papilla, or a degree of anal stenosis, frequently accompany chronic fissures.

Most anal fissures are acute and relatively short-lived, resolving spontaneously or with simple dietary modification to increase fiber and stool-softening laxatives when appropriate. The distinction between acute and chronic fissures is arbitrary and cannot be made reliably solely on the appearance of the fissure. The accepted definition is that fissures failing to heal within 6 weeks despite straightforward dietary measures generally are designated as chronic.<sup>26 Goligher J: Surgery of the Anus, Rectum and Colon. London, Bialliere Tindall

Haga clic aquí para ir a la sección de Referencias, 48 Keighley M, Williams N: Surgery of the Anus, Rectum and Colon. London, WB Saunders

Haga clic aquí para ir a la sección de Referencias</sup>Although a proportion (probably <10%) of chronic fissures eventually resolve with conservative measures, most require further intervention to heal. Fissures usually are single and most commonly arise in the posterior midline, but 10% of women and 1% of men have fissures in the anterior midline.<sup>26 Goligher J: Surgery of the Anus, Rectum and Colon. London, Bialliere Tindall

Haga clic aquí para ir a la sección de Referencias</sup> In particular, women who develop symptoms postpartum (accounting for 3% to 11% of all chronic fissures) tend to have anterior fissures.<sup>31 Graham-Stewart C.W., Greenwood R.K., Lloyd-Davies R.W. Review of 50 patients with fissure-in-ano Surg Gynaecol Obstet 1961 ;  113 : 445-448

Haga clic aquí para ir a la sección de Referencias, 48 Keighley M, Williams N: Surgery of the Anus, Rectum and Colon. London, WB Saunders

Haga clic aquí para ir a la sección de Referencias, 74 Martin J.D. Postpartum anal fissure Lancet 1953 ;  1 : 271-273  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> Multiple fissures or fissures in a lateral position on the anal margin raise suspicion because there may be underlying inflammatory bowel disease, syphilis, or immunosuppression, including human immunodeficiency virus (HIV) infection. It is important to recognize that most fissures arising in patients with inflammatory bowel disease are posterior and are painful in at least 50% of cases.<sup>21 Fleshner P.R., Schoetz D.J.J., Roberts P.L. , y al. Anal fissure in Crohn's disease: A plea for aggressive management Dis Colon Rectum 1995 ;  38 : 1137-1143  [cross-ref]

Haga clic aquí para ir a la sección de Referencias, 105 Sweeney J.L., Ritchie J.K., Nicholls R.J. Anal fissure in Crohn's disease Br J Surg 1988 ;  75 : 56-57  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> Fissures that are resistant to treatment should prompt further investigation, including examination under anesthesia and appropriate biopsy.