Acute Diarrhea

SUMMARY APPROACH

1.  Assess for, and manage, Dehydration
2.  Consider work-up as below
3.  Empiric Antibiotics for bloody diarrhea (while studies pending)
4.  Bloody diarrhea: also consider test for O157:H7 Shiga toxin
5.  Order C. difficile assay if antibiotics or hospitalization in last month
6.  Rarely need O&P
 

Obtain Stool Culture & Sensitivity, and C. difficile Toxin Assay If:

  • Bloody diarrhea
  • Fever
  • Severe abdominal pain
  • Elderly
  • Stool wet prep positive for WBCs (if ordered)
  • Immunocompromised
  • Persistent, profuse diarrhea
  • Maybe food-handlers [if required by job]

Consider Stools for Giardia Angtigen or O&P if:

  • 3rd World Travel:    Giardia, Ameba, Cyclospora
  • Travel to Russia:     Giardia
  • Wilderness hiking:     Giardia
  • Men-having-Sex-with-Men MSM):     Giardia
  • Bloody Diarrhea + 3rd World Travel or MSM:     Ameba
  • AIDS / severely immunocompromised:     All of above
  • Community Outbreak:     Giardia, Cryptosporidium

MICROBIOLOGIC ETIOLOGY OF DIARRHEA

Small Intestine Pathogens

Viruses
  • Norovirus
  • Rotavirus
  • Other viruses
Bacteria
  • Salmonella
  • Clostridium perfringens
  • E. coli (Traveler’s diarrhea, some other strains)
  • Aeromonas
  • Listeria
  • Cholera
Protozoa
  • Giardia
  • Cyclospora
  • Cryptosporidium *
  • Microsporidium *
  • Isospora *

Large Intestine Pathogens

Virus
  • Cytomegalovirus *
Bacteria
  • Shigella
  • Campylobacter
  • Yersinia
  • E. coli (invasive)
  • E. coli (hemorrhagic)
  • C. difficile
Protozoa
  • Entamoeba histolytica (cause of Amebic dysentery)

* = AIDS-related pathogens  (Cryptosporidium also affects immunocompetent persons)

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