What are the indications for antibiotics in acute infectious diarrhea?
Antibiotic use for acute diarrhea depends largely on the infectious agent. In the developed world, most acute diarrhea is self-limited and viral, rendering antibiotics moot. In cases in which a particular pathogen is confirmed or highly suspected ( C. difficile, Giardia, EHEC, ETEC, EIEC, Shigella spp., Isospora, Microsporidia, Cyclospora, E. histolytica ) antibiotics are reasonable. For infections such as nontyphoidal Salmonella, antibiotics lend no benefit and prolong clearance of the pathogen. Unfortunately, most clinicians must make treatment decisions prior to pathogen identification. As such, the clinical presentation and suspected pathogen drive the decision. An empiric fluoroquinolone is reasonable in adults with inflammatory diarrhea not thought to be from STEC. Shiga toxin production may also be readily ruled out in most clinical microbiology laboratories.