Pediatric Gastroenteritis in Emergency Medicine

Updated: Apr 18, 2023
  • Author: Adam C Levine, MD, MPH; Chief Editor: Kirsten A Bechtel, MD  more...
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Practice Essentials

Though often considered a benign disease, acute gastroenteritis remains a leading cause of pediatric morbidity and mortality in children younger than 5 years (higher than other well-known diseases such as malaria, HIV infection, and tuberculosis for the same age group).

Viruses remain by far the most common cause of acute gastroenteritis in children, though several bacterial species also play an important role in acute gastroenteritis, especially in low-resource settings. The two primary mechanisms responsible for acute gastroenteritis are as follows:

  • Damage to the villous brush border of the intestine, causing malabsorption of intestinal contents and leading to osmotic diarrhea

  • Toxins that bind to specific enterocyte receptors and cause the release of chloride ions into the intestinal lumen, leading to secretory diarrhea

Signs and symptoms

These include the following:

  • Diarrhea

  • Vomiting

  • Increase or decrease in urinary frequency

  • Abdominal pain

  • Signs and symptoms of infection - Presence of fever, chills, myalgias, rash, rhinorrhea, sore throat, cough; these may be evidence of systemic infection or sepsis

  • Changes in appearance and behavior - Including weight loss and increased malaise, lethargy, or irritability, as well as changes in the amount and frequency of feeding and in the child’s level of thirst

  • History of recent antibiotic use - Increases the likelihood of Clostridium difficile infection

  • History of travel to endemic areas

See Clinical Presentation for more detail.


Assessment should begin by determining the severity of dehydration using a well-validated clinical scale such as the Dehydration: Assessing Kids Accurately (DHAKA) score or the Clinical Dehydration Scale (CDS). Stool culture may be helpful in children presenting with bloody diarrhea or recent travel to a low-resource setting. Children older than 12 months of age with a recent history of antibiotic use should have stool tested for C difficile toxins. Those with a history of prolonged watery diarrhea (>14 days) or travel to an endemic area should have stool sent for ova and parasites or molecular testing for intestinal parasites. Any child with evidence of systemic infection (ie, sepsis) should have a complete workup, including complete blood count (CBC), stool cultures, and blood cultures. If indicated, urine cultures, chest radiography, and/or lumbar puncture should be performed.

See Workup for more detail.


Oral rehydration solution

The American Academy of Pediatrics, the European Society of Pediatric Gastroenterology and Nutrition (ESPGAN), and the World Health Organization (WHO) all recommend oral rehydration solution (ORS) as the treatment of choice for children with mild to moderate gastroenteritis, including those in both high-resource and low-resource settings, based on the results of dozens of randomized, controlled trials and several large meta-analyses. Intravenous fluids should be reserved for patients with objective signs of severe dehydration or shock.

Pharmacologic therapy

Agents used in the treatment or prevention of acute pediatric gastroenteritis include the following:

  • Vaccines - Both the RotaTeq and Rotarix vaccines are available and effective for the prevention of rotavirus gastroenteritis

  • Oral vancomycin - Recommended in patients infected with C difficile

  • Tinidazole and metronidazole - Recommended in patients with Giardia infection

  • Tetracycline and doxycycline - Recommended in patients with cholera (azithromycin should be used for children younger than 8 years)

  • Ciprofloxacin - Recommended in patients with Shigella infection

  • Ondansetron - Effective for the management of vomiting in children with acute gastroenteritis, reducing the need for intravenous fluids

  • Zinc - WHO and two systematic reviews support zinc supplementation for all children younger than 5 years with acute gastroenteritis in low-resource settings, though little data exist to support this recommendation for children in high-resource settings

See Treatment and Medication for more detail.



Though often considered a benign disease, acute gastroenteritis remains a leading cause of morbidity and mortality in children around the world. Because the disease severity depends on the degree of fluid loss, accurately assessing dehydration status and appropriately rehydrating patients remains a crucial step in preventing morbidity and mortality. Luckily, most cases of dehydration in children can be accurately diagnosed by a careful clinical examination and treated with simple, cost-effective measures.




Adequate fluid balance in humans depends on the secretion and reabsorption of fluid and electrolytes in the intestinal tract; diarrhea occurs when intestinal fluid output overwhelms the absorptive capacity of the gastrointestinal tract. The 2 primary mechanisms responsible for acute gastroenteritis are (1) damage to the villous brush border of the intestine, causing malabsorption of intestinal contents and leading to an osmotic diarrhea, and (2) the release of toxins that bind to specific enterocyte receptors and cause the release of chloride ions into the intestinal lumen, leading to secretory diarrhea.

However, even in severe diarrhea, various sodium-coupled solute co-transport mechanisms remain intact, allowing for the efficient reabsorption of salt and water. By providing a 1:1 proportion of sodium to glucose, classic oral rehydration solution (ORS) takes advantage of a specific sodium-glucose transporter (SGLT-1) to increase the reabsorption of sodium, which leads to the passive reabsorption of water. Rice- and cereal-based ORS may also take advantage of sodium-amino acid transporters to increase reabsorption of fluid and electrolytes.



By far, viruses remain the most common cause of acute gastroenteritis in children, both in high-resource and low-resource settings. In the United States, routine rotavirus vaccination has led to a 60-98% reduction in pediatric rotavirus hospitalization since 2006. [1]  With the continued decline of rotavirus-associated gastroenteritis since the introduction of rotavirus vaccines, noroviruses (Norwalk-like viruses) have become the leading cause of medically attended acute gastroenteritis in children younger than 18 years, accounting for 24,000 hospitalizations, 132,000 emergency department visits, 925,000 outpatient visits, and more than $200 million in treatment costs each year. [2, 3]  Approximately half of the norovirus-related visits involved children aged 6-18 months according to a study from the US Centers for Disease Control and Prevention (CDC). [4, 5, 6]  It has been estimated that norovirus results in $60.3 billion in societal costs per year, with the Americas having the highest cost at $23.5 billion. [7]  Annually, norovirus outbreaks cost approximately $173.5 million, with productivity losses representing 95% and direct medical costs representing 4% of total outbreak costs. [8]

Caliciviruses, astroviruses, and enteric adenoviruses make up the remainder of cases of viral gastroenteritis. For children aged < 2 years, astrovirus and sapovirus were detected significantly more in children with acute gastroenteritis than in age-matched healthy controls in the United States. [9]  Viral gastroenteritis typically presents with low-grade fever and vomiting followed by copious watery diarrhea (up to 10-20 bowel movements per day), with symptoms persisting for 3-8 days. [10]

In high-resource settings, bacterial pathogens account for a small portion, perhaps 2-10%, of all cases of pediatric gastroenteritis. In the United States, the most prevalent bacterial pathogens for children under 19 years of age in 2021 included Salmonella, Campylobacter, Shiga toxin-producing Escherichia coli (STEC), Shigella, and Yersinia. [11]  Relative to viral gastroenteritis, bacterial disease is more likely to be associated with high fevers, shaking chills, bloody bowel movements (dysentery), abdominal cramping, and fecal leukocytes. [12]

Globally, diarrhea is responsible for more than 1 billion cases of illness and over half a million deaths among children under 5 years of age each year, with approximately 88% of these deaths occurring in South Asia and sub-Saharan Africa. [13]  Although the prevalence of enteropathogens in both these regions is dependent on age, geography, and seasonality (ie, dry versus rainy seasons), both South Asia and sub-Saharan Africa share common etiologies of acute diarrhea. [13, 14, 15]  Several multisite cohort studies in low-income and middle-income countries found Shigella, Campylobacter jejuni, and enterotoxigenic Escherichia coli (ETEC) to be the most prevalent bacterial pathogens, whereas rotavirus, adenovirus, norovirus, and sapovirus are the most prevalent viral pathogens associated with acute diarrhea. [15, 16, 17, 18, 19, 20]  Shigella and rotavirus were the leading bacterial and viral etiology for diarrhea mortality, respectively, among children under 5 years of age in low- and middle-income countries. [20]

Antibiotic-associated diarrhea (AAD) has become a common complication among children. Although studies have suggested the use of probiotics can reduce the risk of AAD in children, several studies recommend further research. [21, 22]  In children, C difficile has emerged as an important cause of AAD, accounting for 22-30% of AAD cases. [23]  However, rates may be higher, as C difficile testing in infants younger than 1 year of age is not recommended, owing to the high rates of colonization (37%). The rate of colonization decreases as age increases. [24]  Any antibiotic can increase the risk of C difficile infection; however, cephalosporins, fluoroquinolones, clindamycin, and certain penicillins (ie, co-amoxiclav) appear to increase risk the most. [25]          

Parasites remain yet another source of gastroenteritis in young children, with Giardia and Cryptosporidium the most common causes in the United States. Parasitic gastroenteritis generally presents with watery stools but can be differentiated from viral gastroenteritis by a protracted course or history of travel to endemic areas. [10, 26, 27]



Most cases of acute gastroenteritis follow a relatively benign course, with less than 2% of diarrheal episodes progressing to severe disease. Even among children who develop severe diarrhea, mortality is only about 2%. Younger children under 2 years of age tend to be at higher risk for death. In all cases, early and appropriate rehydration can reduce mortality in both high- and low-resource settings.


Patient Education

Parents should be reassured that acute gastroenteritis is generally a benign disease, and in most cases it will improve on its own within 1 week without specific treatment. For children without signs of dehydration who are being discharged home, parents should be told to continue breastfeeding/general feeding of the child, and they can encourage extra fluid intake as long as the child tolerates. Parents should be told to return if their child develops intractable vomiting, signs of more severe dehydration such as irritability or lethargy, sunken eyes, reduced skin pinch, decreased tears, or refusal to drink fluids. Parents should also be told to return if the child develops high fevers, seizures, worsening abdominal pain, or bloody diarrhea, or if the diarrhea continues to persist beyond 1-2 weeks.