Snapshot A 2-year-old girl presents to the emergency room for diarrhea and abnormal behavior. Her mother reports that she had been having watery diarrhea for the past 2 days with some nonbloody vomiting. Although she has been encouraging the patient to drink more fluids, she has been resistant. Today, the patient is sleepier than usual, and her urine output is also less than usual. On physical exam, she has sunken eyes and dry mucous membranes. She has an episode of diarrhea while in the emergency room. She is given intravenous hydration. Introduction Classification rotavirus a segmented double-stranded RNA virus a reovirus causes gastroenteritis transmitted via fecal-oral highly contagious Epidemiology incidence high in the winter demographics most common in infants and children risk factors daycare center kindergarten contact with children Pathogenesis the virus causes gastrointestinal villous atrophy, leading to decreased absorption of sodium and loss of potassium this causes a nonbloody diarrhea Associated conditions rotavirus vaccine is associated with intussusception Prevention vaccination live-attenuated vaccine recommended for all infants contraindicated in those with intussusception or severe combined immunodeficiency Prognosis can be fatal in children usually resolves within a week Presentation Symptoms watery diarrhea vomiting Physical exam low-grade fever dehydration Studies Labs stool rotavirus antigen not always needed Making the diagnosis based on clinical presentation definitive diagnosis is usually not needed Differential Norovirus distinguishing factors typically lasts only 1-3 days rather than a week Treatment Management approach mainstay of treatment is supportive care Conservative supportive care indication all patients modalities hydration antiemetics isolation precautions Complications Shock Intussusception