Encopresis Workup

Updated: Oct 20, 2017
  • Author: Stephen M Borowitz, MD; Chief Editor: Carmen Cuffari, MD  more...
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Approach Considerations

In most patients, the diagnosis of encopresis is established in the basis of the history and complete physical examination, including a rectal examination.

Laboratory studies are rarely warranted, though radiography, manometry, and biopsy may be helpful.


Abdominal Radiography

Plain abdominal radiography may be helpful in determining whether a soft fecal impaction is present. This study can be very useful for documenting the nature of the problem and helping explain it to an older child and his or her parents, particularly when a history of constipation is not evident or is denied.


Anorectal Manometry

Anorectal manometry is sometimes helpful in delineating the child’s defecation dynamics. [15] Many children with encopresis have evidence of megarectum, as evidenced by diminished sensation to distention of the rectum during balloon insufflation. Many children who have encopresis also have paradoxical constriction of the external anal sphincter (EAS) during attempted defecation.

Anorectal manometry can also be helpful in excluding ultrashort-segment Hirschsprung disease, which is a rare cause of encopresis. With this disorder, intramural ganglion cells in the submucosa and myenteric plexuses of the distal colon are absent. In the absence of these ganglion cells, the internal anal sphincter does not relax in response to rectal distention by balloon inflation.



Although Hirschsprung disease is rarely associated with encopresis, this diagnosis, if suspected, can be excluded by identifying ganglion cells in the submucosa and myenteric plexuses of the rectum.

A biopsy specimen can be obtained either by surgical means or through the use of a suction device.