Takeaways:

The BioFire FilmArray GI PCR panel is extremely sensitive and specific, more than traditional testing.
Viral pathogens dominate in younger children < 5 years, in winter months, and with vomiting.
Bacterial pathogens are more likely in older children, summer months, and with diarrhea.
A bacterial etiology is more likely with multiple severe clinical factors.
If concerned for a protozoal etiology or a severe bacterial etiology, antimicrobial therapy or another change in management may be indicated.

References:

Stockmann C, et al. Detection of 23 Gastrointestinal Pathogens Among Children Who Present With Diarrhea. J Pediatric Infect Dis Soc. 2016 May 4. pii: piw020. [Epub ahead of print]