General Information:

• Acute diarrheal illness is a common cause of morbidity and mortality disproportionately affecting low and middle income countries
• Acute diarrhea poses the greatest threat to the immunocompromised, children, and the elderly
• Stool samples are costly and frequently don’t provide information altering the course of treatment in acute, non-severe diarrhea
• However, for acute diarrhea, a single stool sample should be obtained when diarrhea is associated with:
• fever (≥38.5°C)
• a severe coexisting condition in a hospitalized patient on antibiotics
• persistent diarrhea (≥14 days)
• profuse cholera-like watery diarrhea
• dehydration
• dysentery
• an elderly or immunocompromised patient
• food handlers, nursing home residents, and daycare workers
• The stool sample must be processed by the lab within 4 hours to directly visualize parasites and within 12 hours for routine microbiologic staining.

Bottom Line for the EM Physician:  Use these guidelines to test stool only when helpful to patient care and avoid flushing resources down the toilet.

University of Maryland Section of Global Emergency Health

Author:  Alex Skog

References

DuPont HL. Acute infectious diarrhea in immunocompetent adults. N Engl J Med. 2014 Apr 17;370(16):1532–40.

Fischer Walker CL, Perin J, Aryee MJ, Boschi-Pinto C, Black RE. Diarrhea incidence in low- and middle-income countries in 1990 and 2010: a systematic review. BMC Public Health. 2012;12:220.