Acute gastroenteritis is a common infection in childhood. The majority of cases are caused by viruses, while ∼20% are bacterial, and a small number are parasitic. Most children have a mild presentation where nausea, vomiting, and diarrhea are not severe enough to prevent adequate oral intake or participation in normal activities. Severe disease is characterized by , end-organ damage, fevers ≥ 40°C, signs of sepsis, bloody or bilious emesis, and toxic appearance. Children with mild-to-moderate gastroenteritis can be diagnosed clinically. Children with severe illness, atypical presentations, or should undergo laboratory studies. Treatment is usually supportive with fluid replacement, antiemetics, and antipyretics. Antimicrobial therapy (empiric or tailored) may be utilized for children with suspected or confirmed bacterial or parasitic infections. Prevention of infectious gastroenteritis involves vaccination of infants against rotavirus, travel vaccines where appropriate, and patient/caregiver education on hand hygiene and food and water hygiene.
- Common illness in children, causing each year: 
- > 1.5 million outpatient visits
- ∼ 200,000 hospitalizations
- Severe illness is more common in children < 5 years of age. 
Epidemiological data refers to the US, unless otherwise specified.
- in children are similar to adults and typically include:
- In children, additional clinical features that raise concern for severe illness include: 
- Diagnosis is usually clinical.
- Consider in children with: 
- Assess for ; if present, order . 
|Clinical dehydration scale for acute gastroenteritis in children ≤ 5 years of age |
|Thirsty, restless, and/or lethargic but irritable with stimuli||1|
|Cold, sweaty, drowsy, limp, or unarousable||2|
|Tacky or sticky||1|
Diagnosis of viral gastroenteritis in children is usually clinical; are not routinely indicated. 
Treatment of infectious gastroenteritis in children is generally supportive.
All patients 
- Determine the need for admission, e.g., patients with:
- Inability to manage symptoms at home
- Provide symptomatic treatment.
- Consider antimicrobial therapy for select patients. 
- Optimize nutrition.
- Educate patients and/or caregivers on preventing onward transmission of gastroenteritis.
- Encourage fluid intake.
- Give oral rehydration solution (ORS) if are present. 
- Advise caregivers to seek medical assistance if develop.
Severe gastroenteritis or children with 
- Admit to hospital and initiate .
- Identify patients in shock and start .
- Initiate IV fluids or . and with either