megacolon


megacolon

      massive enlargement and dilation of the large intestine (colon). The two main types of the syndrome are congenital megacolon, or Hirschsprung disease, and acquired megacolon. In congenital megacolon, the lowermost portion of the large intestine is congenitally lacking in normal nerve fibres; thus, peristalsis, or involuntary contractions, of the muscles of this part of the intestine cannot occur, and the bowel's contents are not pushed onward. The area of normal intestine above the abnormal part works harder to push on the fecal contents, with the result that the muscular walls of that part of the intestine become enlarged and thickened. The entire colon eventually becomes thick and distended. The symptoms of congenital megacolon include a distended abdomen and severe constipation in infants born with the disorder.

      Acquired megacolon in children (childhood disease and disorder) characteristically results from a combination of faulty toilet training and mental or emotional disturbances that result in a child's refusing to try to defecate. The administration of increasingly larger doses of laxatives fails to solve the problem permanently, and over time the child's rectum becomes filled with impacted feces and the colon becomes progressively enlarged. Once the distended bowel has been emptied, the treatment for this disorder is primarily psychiatric and involves persuading the child to accept bowel training.

      Megacolon in adults can result from taking certain medications, abnormal thyroid (thyroid gland) function, diabetes mellitus, scleroderma, or amyloidosis. Various surgical procedures are used to correct the condition.

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Universalium. 2010.

Look at other dictionaries:

  • Megacolon — Classification and external resources ICD 10 K59.3 ICD 9 564.7 …   Wikipedia

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  • Mégacôlon — toxique Le mégacôlon toxique (megacolon toxicum) est une complication possiblement fatale d autres conditions intestinales. Il est caractérisé par un côlon très dilaté (mégacôlon), accompagné d une dilatation de l abdomen (gonflement), et parfois …   Wikipédia en Français

  • megacolon — m. anat. patol. Tamaño anormalmente grande del colon o dilatación de una parte más o menos extensa del colon. Cursa con estreñimiento y puede ser congénita o adquirida. Medical Dictionary. 2011. megacolon …   Diccionario médico

  • mégacôlon — [ megakolɔ̃ ] n. m. • 1901; de méga et côlon ♦ Méd. Dilatation anormale du gros intestin, accompagnée d un épaississement de la paroi. ● mégacôlon nom masculin Dilatation importante et permanente d un segment du côlon, parfois congénitale,… …   Encyclopédie Universelle

  • Megacolon — Klassifikation nach ICD 10 Q43.1 Hirschsprung Krankheit Aganglionose Megacolon congenitum (aganglionär) B57.3 Chagas Krankheit (chronisch) mit Beteiligung des Verdauungssystems …   Deutsch Wikipedia

  • megacolon — A condition of extreme dilation of the colon. SYN: giant colon. acquired m. m. occurring on the basis of an acquired disease; occurs in inflammatory bowel disease (toxic m.) and Chagas …   Medical dictionary

  • megacolon — n. dilatation, and sometimes lengthening, of the colon. It is caused by obstruction of the colon, Hirschsprung s disease, or longstanding constipation, or it may occur as a complication of ulcerative colitis (toxic megacolon) …   The new mediacal dictionary

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