When are fecal cultures or PCR panels indicated in chronic diarrhea workups?

When are fecal cultures or PCR panels indicated in chronic diarrhea workups?

• A. Only when infectious disease is strongly suspected
• B. For all chronic diarrhea cases
• C. Only after radiographs show abnormalities
• D. Never check for infectious disease

Answer: (A)

Stool pathogen testing is reserved for when there is a believable infectious cause based on the patient’s history and risk factors. In chronic diarrhea, many cases stem from noninfectious processes, so ordering fecal cultures or a broad PCR panel for every patient would add cost and may have limited yield. Testing is most appropriate if there are clues such as recent antibiotic use or hospitalization, travel to areas with enteric infections, exposure to known outbreaks, immunocompromised status, or symptoms like fever, nocturnal stools, blood or weight loss. When these clues aren’t present, the likelihood of an infectious etiology is lower, and routine stool testing isn’t routinely recommended. Radiographic abnormalities don’t by themselves mandate stool infectious studies, and it’s not accurate to say never check for infection, since occult infections can occur, especially in at-risk individuals.

Stool pathogen testing is reserved for when there is a believable infectious cause based on the patient’s history and risk factors. In chronic diarrhea, many cases stem from noninfectious processes, so ordering fecal cultures or a broad PCR panel for every patient would add cost and may have limited yield. Testing is most appropriate if there are clues such as recent antibiotic use or hospitalization, travel to areas with enteric infections, exposure to known outbreaks, immunocompromised status, or symptoms like fever, nocturnal stools, blood or weight loss. When these clues aren’t present, the likelihood of an infectious etiology is lower, and routine stool testing isn’t routinely recommended. Radiographic abnormalities don’t by themselves mandate stool infectious studies, and it’s not accurate to say never check for infection, since occult infections can occur, especially in at-risk individuals.