Which patients should have a stool culture?

• severe diarrhea (passage of six or more unformed stools per day)
• diarrhea of any severity that persists for longer than a week
  
• fever
• bloody diarrhea
  
• multiple cases of illness that suggest an outbreak
  

Stool cultures are not routinely recommended in most cases of watery diarrhea or traveler's diarrhea.


Source

DuPont, H. "Bacterial Diarrhea" New England Journal of Medicine. 15 Oct 2009.