The guidelines make it clear that most people with diarrhea can be treated empirically with attention to hydration. For diarrhea accompanied by fever, bloody or mucoid stools, severe abdominal cramping or tenderness, or signs of sepsis, stool testing should be performed. Tests should be done for Salmonella, Shigella, Campylobacter, Yersinia, C. difficile, and Shiga toxin producing E. coli. For immunocompromised people with diarrhea, a different approach with a broad differential is recommended, including consideration of infections with Cryptosporidium, Cyclospora, Cystoisospora, microsporidia, Mycobacterium avium complex, and cytomegalovirus (CMV). While travelers’ diarrhea does not require diagnostic testing, travelers’ diarrhea lasting 14 days or longer should be evaluated for intestinal parasitic infections. In immunocompetent children and adults, empiric antimicrobial therapy for bloody diarrhea while waiting for results of investigations is not recommended, except in the case of infants below 3 months of age or in that of an individual who is particularly ill and has fever, abdominal pain, bloody diarrhea, and frequent bloody stools, which might be due to Shigella. When empiric treatment is recommended, either a fluoroquinolone such as ciprofloxacin, or azithromycin are considered reasonable choices. For more information, the Infectious Diseases Society of America has produced a podcast of the guidelines that runs about 20 minutes which is available at: https://itunes.apple.com/us/podcast/infectious-diseases-society-of-america-guideline-update/id519582740?mt=2. —Neil Skolnik, MD