Snapshot A 3-year-old boy with no significant past medical history is brought to urgent care for 2 days of watery diarrhea. He had been attending daycare 2 times a week, and several other kids have also experienced similar symptoms. He has had 5-6 bowel movements per day and has not been able to eat much. His parents have been encouraging him to drink oral electrolyte solution. On physical exam, he is noted to have sunken eyes, poor skin turgor, and increased capillary refill time. Introduction Overview acute diarrhea is characterized by acute onset of > 3 bowel movements/day lasting < 14 days and is often caused by infection persistent diarrhea lasts 2-4 weeks chronic diarrhea lasts > 4 weeks and is often caused by underlying conditions such as inflammatory bowel disease or fat malabsorption Epidemiology Incidence very common rotavirus is most common cause of infectious diarrhea worldwide login to view 1 more bullet acute diarrhea is the second cause of childhood mortality in the world Demographics viral diarrhea is most common in children login to view 1 more bullet Etiology Infections viruses bacteria parasites Drug-induced quinidine colchicine cytotoxic agents chemotherapy Food allergies Toxic ingestions Autoimmune Small intestine bacterial overgrowth, often secondary to scleroderma or diabetes Pathogenesis types of diarrhea exudative/inflammatory diarrhea login to view 6 more bullets fatty diarrhea login to view 3 more bullets watery diarrhea login to view 13 more bullets Infectious Bloody Vs Watery Diarrhea Bloody Diarrhea Watery Diarrhea Campylobacter E. histolytica Enterohemorrhagic E. coli Enteroinvasive E. coli Non-thypoidal Salmonella Shigella Y. enterocolitica C. difficile C. perfringens Enterotoxigenic E. coli Giardia Cryptosporidium V. cholerae Rotavirus Norovirus Adenovirus S. aureus High Yield Risk Factors Exposure Risk Factors Associated Organisms Daycare Rotavirus, astrovirus, calicivirus, Campylobacter, Shigella, Giardia, Cryptosporidium Food Dairy Eggs Beef Poultry Pork Seafood Oysters Rice/Pasta Campylobacter and Salmonella Salmonella E. coli Campylobacter C. perfringens Y. enterocolitica Astrovirus Vibrio Calicivirus Bacillus cereus Water exposure Swimming Pools Contaminated water with cysts Shigella Giardia, E. histolytica, and Cryptosporidium Travel history "Traveler's" diarrhea Cruise ships Camping/hiking E. coli, Giardia, Salmonella, Shigella, and Campylobacter Norovirus Giardia Past medical history Antibiotics/hospitalization C. difficile and rotavirus Pets Dog feces Turtles/reptiles Other animals/pets Yersinia enterocolitica Non-typhoidal Salmonella Campylobacter Presentation Symptoms common symptoms login to view 11 more bullets Physical exam inspection login to view 4 more bullets Studies Acute diarrhea does not routinely require laboratory evaluation, unless clinical presentation includes high fever bloody diarrhea severe abdominal pain requires hospitalization elderly immunocompromised status Serum labs complete blood count Stool studies ova and parasite examination C. difficile toxin leukocyte presence suggests enteroinvasive infection pH < 5.5 usually indicates viral illness and can also indicate lactase deficiency culture enzyme immunoassay for rotavirus and adenovirus antigens latex agglutination assay for rotavirus Differential Chronic diarrhea, which lasts 4 weeks or more, suggests other etiologies, such as fat malabsorption syndrome Radiation injury high doses of radiation classically cause diarrhea and lymphopenia (poor prognosis) Chronic DiarrheaMalabsorption syndromesCeliac diseaseLactose intolerancePancreatic insufficiencyDiabetic neuropathyInflammatory bowel diseaseCrohn diseaseUlcerative colitisOther gastrointestinal causesMicroscopic colitisIrritable bowel syndromeEndocrinologicalCarcinoidGastrinomaDrug-inducedQuinidineColchicineChemotherapyOtherSevere combined immunodeficiencyArsenic poisoningVitamin C toxicityVitamin B3 deficiency Treatment Medical supportive care login to view 5 more bullets antibiotics login to view 5 more bullets anti-motility agents login to view 6 more bullets Complications Dehydration