Shigellosis Workup

Updated: Jun 17, 2019
  • Author: Joyann A Kroser, MD, FACP, FACG, AGAF; Chief Editor: BS Anand, MD  more...
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Laboratory Studies

Laboratory studies generally reveal the following findings:

  • Fecal leukocytes and erythrocytes

  • Mildly elevated hematocrit, sodium, and urea nitrogen levels are indicative of volume depletion in cases of shigellosis.

  • Leukocytosis is rare.

  • Positive findings on stool culture of a fresh fecal specimen

  • In patients who are immunocompromised (eg, infected with human immunodeficiency virus [HIV]), blood cultures are rarely helpful in cases of shigellosis.



Sigmoidoscopy is not necessary in most cases of shigellosis.

If distinguishing between dysentery and the acute presentation of idiopathic ulcerative colitis is urgently necessary, a colonic biopsy may be useful if it is performed within 4 days of the onset of symptoms. Histologic findings of shigellosis include the following:

  • Intense neutrophilic and mononuclear cells infiltrating the lamina propria

  • Hemorrhage

  • Ulcers

  • Mucous depletion

  • Occasional crypt abscesses