Diarrhea - a podcast by Tim Horeczko, MD, MSCR, FACEP, FAAP

Traditional Approach:

Secretory -- poisoned mucosal villi -- "the sieve"

Cytotoxic -- destroyed mucosal villi -- "the shred"

Osmotic -- malabsorption -- "the pull"

Inflammatory -- edema, motility -- "the push"

Lots of overlap, difficult to apply to clinical signs and symptoms.

Bedside Approach:

Fever/No Fever, Bloody/No Blood

Non-bloody, febrile -- most likely viral

Non-bloody, afebrile -- may be viral

Bloody, febrile -- likely bacterial

Non-bloody, afebrile -- full stop.  Eval for Hemolytic Uremic Syndrome

Workup

Ask yourself -- again -- why is this not... appendicitis-torsion-intussusception-etc.

Admit sick children, but most go home, so...

Non-bloody, febrile -- no workup necessary; precautionary advice 

Non-bloody, afebrile -- be more skeptical, but generally same as above

Bloody, febrile -- stool culture, follow up; do not treat empirically unless septic and admitted.  Culture will dictate treat/no treat/how.

Bloody, afebrile -- evaluate for hemolytic uremic syndrome, especially if under 5 years old: CBC, chemistries, UA, stool culture

Evaluate Hydration Status

Selected References

Khan WA et al. Central Nervous System Manifestations of Childhood Shigellosis: Prevalence, Risk Factors, and Outcome. Pediatrics. 1999 Feb;103(2):E18

Lee JY et al. Diagnostic yield of stool culture and predictive factors for positive culture in patients with diarrheal illness. Medicine (Baltimore). 2017 Jul; 96(30): e7641.

Nelson JD et al. Treatment of Salmonella gastroenteritis with ampicillin, amoxicillin, or placebo. Pediatrics 1980; 65:1125.