Indications for Testing

Stool testing is generally indicated for diarrheal illness in:

1) Patients with bloody diarrhea (testing for bacterial pathogens)
2) Patients with clinical or laboratory signs suggestive of shiga-toxin producing E. coli (i.e. O157)
3) Any patient with diarrheal illness and signs of sepsis
4) Diarrheal illnesses lasting > 14 days (including testing for parasites)
5) Patients with specific exposures (ie. shellfish ingestion, outbreaks, undercooked meat)
6) Immunocompromised patients (testing should include viruses, bacteria and parasites)
7) International travelers if: above conditions are met, travel to known cholera endemic area or travel to typhoid (enteric) fever endemic area (Salmonella typhi)

Blood cultures are indicated less often but should be considered for: infants < 3months of age with suspected bacterial etiology, travelers with suspected typhoid fever, patients with diarrheal illness and suspected sepsis, and immunocompromised patients (including patients with hemoglobinopathies/hemolytic anemia with fever and diarrheal illness.)