Synonyms
Anal cushions; Piles
Definition
Hemorrhoids or anal cushions are anatomical structures located in the distal portion of the rectum and the anus, composed of a network of vascular channels without muscular wall (sinusoids), elastic and connective tissue, and smooth muscle fibers (submucosal Trietz’s muscle). The term “hemorrhoids” is currently not used for a pathological state and represents a normal feature of the anal region with a role in maintaining the anal canal closed and contributing to fecal continence.
Anal cushions become pathological when abnormal changes like swelling and inflammation (sometimes followed by hemorrhage and thrombosis) take place.
Internal hemorrhoids have their origins in the superior hemorrhoid plexus of the lower part of the rectum, while external hemorrhoids are located under the anorectal line or dentate line.
Symptomatic hemorrhoids are caused by increased intra-abdominal pressure such as that occurring in the straining of bowel movements,...
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American Gastroenterological Association medical position statement. (2004). Diagnosis and treatment of hemorrhoids. Gastroenterology, 126, 1461–1462.
Kaidar-Person, O., Person, B., & Wexner, S. D. (2007). Hemorrhoidal disease: A comprehensive review. Journal of the American College of Surgeons, 204(1), 102–117.
Lohsiriwat, V. (2012). Hemorrhoids: From basic pathophysiology to clinical management. World Journal of Gastroenterology, 18(17), 2009–2017.
Schubert, M. C., Sridhar, S., Schade, R. R., & Wexner, S. D. (2009). What every gastroenterologist needs to know about common anorectal disorders. World Journal of Gastroenterology, 15(26), 3201–3209.
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Becheanu, G. (2017). Hemorrhoids. In: Carneiro, F., Chaves, P., Ensari, A. (eds) Pathology of the Gastrointestinal Tract. Encyclopedia of Pathology. Springer, Cham. https://doi.org/10.1007/978-3-319-40560-5_1482
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DOI: https://doi.org/10.1007/978-3-319-40560-5_1482
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