Chronic Megacolon Clinical Presentation

Updated: Sep 25, 2019
  • Author: David Manuel, MD; Chief Editor: BS Anand, MD  more...
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History and Physical Examination

Historically, chronic megacolon has been categorized into two groups, according to when symptoms begin. The congenital group experiences onset of constipation before the age of 1 year. The acquired group develops symptoms after age 10 years until adulthood.

Physical examination generally reveals a distended abdomen, which may or may not be tense. Tympany is invariably present.

Digital rectal examination may demonstrate a hard mass of stool just above the anorectal ring. Digital rectal examination in a patient with Hirschsprung disease may bring about a large gush of retained fecal material.

Megarectum with a rectum distended with stool, if chronic, tends to cause the anus to gape open secondary to the dysfunction of the internal sphincter mechanism. These patients may present with factitious diarrhea secondary to overflow incontinence.