Treatment Guideline Chart
Acute gastroenteritis is a diarrheal disease of rapid onset.
Viruses are one of the common causes of acute gastroenteritis.
Rotavirus, norovirus/"Norwalk-like" virus, sapovirus, enteric adenovirus serotypes 40 and 41, astrovirus, calicivirus and enterovirus are the established viral agents causing gastroenteritis.
Rotavirus is the most common pathogen causing diarrhea in patients 3-24 months old.
Patients <3 months old are protected by maternal rotavirus antibodies that are passed transplacentally and possibly by breastfeeding.
Transmission is through fecal-oral route.

Gastroenteritis%20-%20viral Diagnosis


  • Diagnosis can be made on the basis of detailed history and thorough physical exam


  • Assess the onset, duration, frequency, quantity and character of vomiting and diarrhea
  • Recent oral intake, urine output
  • Consumption of contaminated food or drink 
  • History of recent infections, recent antibiotic use 
  • Exposure to family members or individuals with diarrhea
  • Coexisting illness (eg immunodeficiencies, bone marrow transplant)
  • Status of immunization
  • Daycare attendance
  • Community gastroenteritis outbreak 
  • Recent travel to a diarrhea-endemic area 

Physical Examination

  • Vital signs
    • Temperature, heart rate, respiratory rate, blood pressure 
    • Actual body weight change by measuring the actual and pre-illness body weight
      • Considered the gold standard measure of dehydration
  • Signs of dehydration (eg sunken eyes, dry mucous membranes, decreased tears, skin tenting, doughy feel to the skin)
    • Tenting of the skin is associated with isonatremic dehydration; doughy skin is a distinctive feature of hypernatremic dehydration
  • Observe for changes in mental status
  • Check for abdominal distension and tenderness, listen for bowel sounds

Laboratory Tests

  • Not routinely done
  • Certain laboratory exams may be done when the underlying diagnosis is unclear
    • Stool culture should be considered in those with high fever and bloody diarrhea 
    • Complete blood count and blood culture should be considered if suspecting sepsis 
    • May also be necessary for surveillance
  • Most widely used assays for viral pathogen detection are the following: Electron microscopy, enzyme immunoassay, latex agglutination, gel electrophoresis, viral culture (especially for detection of enteric adenovirus, enterovirus, parechovirus, and cytomegalovirus), polymerase chain reaction (PCR), reverse transcription-PCR, nucleic acid amplification test
  • Freshly obtained stool sample is preferred for identification of offending pathogen 
  • Serum electrolytes (eg bicarbonate, sodium), creatinine and glucose may be useful in assessing moderate to severe dehydration especially in patients who require intravenous (IV) or nasogastric (NG) fluids
    • May also be done in patients whose histories and/or physical findings are inconsistent with their diarrheal episodes



  • To provide basis of treatment
  • To identify patients who can safely be sent home for therapy, who should remain for observation during therapy and who may need hospitalization for intensive therapy

Dehydration Assessment 

  • Isotonic dehydration is a common finding in patients with rotavirus gastroenteritis

Minimal or No Dehydration 

  • Consists of <3% loss of body weight (<5% in infants)
  • Normal heart rate (HR), respiratory rate (RR) and pulse volume
  • Normal eyes with presence of tears, moist mucous membranes
  • Normal capillary refill
  • Normal to decreased urine output
  • Patient is well and alert

Mild to Moderate Dehydration 

  • Consists of 6% loss of body weight (5-10% in infants)
  • Normal to increased HR, RR
  • Normal to decreased pulse volume
  • Slightly sunken eyes with decreased tears, sticky mucous membranes
  • Delayed capillary refill 
  • Decreased urine output
  • Patient may appear normal, listless or fatigued

Severe Dehydration 

  • Consists of >9% loss of body weight (>10% in infants)
  • Tachycardia with bradycardia especially in severe cases, deep respirations
  • Thready to absent pulse
  • Deeply sunken eyes with absence of tears, parched mucous membranes
  • Poor capillary refill
  • Minimal urine output
  • Patient may appear lethargic to comatose
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