eMedicine Specialties > Emergency Medicine > Pediatric

Pediatrics, Gastroenteritis

Author: Adam Levine, MD, MPH, Resident Physician, Department of Emergency Medicine, Brigham and Women's Hospital
Coauthor(s): Karen A Santucci, MD, Fellowship Director of Pediatric Emergency Medicine, Department of Pediatrics, Assistant Professor, New Haven Children's Hospital, Yale University
Contributor Information and Disclosures

Updated: Jun 16, 2008

Introduction

Background

Although often considered a benign disease, acute gastroenteritis remains a major cause of morbidity and mortality in children around the world, accounting for 1.8 million deaths annually in children younger than 5 years, or roughly 17% of all child deaths. Because the severity of the disease can widely vary depending on the volume of fluid loss, accurately assessing and treating dehydration in children presenting with acute gastroenteritis remains a critical skill for every emergency physician. Luckily, most cases of dehydration in children can be accurately diagnosed by a careful clinical examination and treated with simple, cost-effective measures.

Pathophysiology

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 GI tract. The 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.

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

Frequency

United States

In the United States, acute gastroenteritis remains a major cause of morbidity in children, accounting for more than 1.5 million outpatient visits, 200,000 hospitalizations, and 300 deaths each year.

International

Worldwide, children younger than 5 years suffer from an estimated 1.4 billion episodes of diarrhea each year, leading to 123 million clinic visits, 9 million hospitalizations, and 1.8 million deaths. Although the absolute number of cases of acute gastroenteritis has changed little over the past 4 decades, the mortality has declined sharply, from 4.6 million in the 1970s to 3 million in the 1980s to 2.5 million in the 1990s.

One of the most important reasons for this decline has been the increasing international support for the use of ORS as the treatment of choice for acute diarrhea, with the proportion of diarrheal episodes treated with ORS rising from 15% in 1984 to 40% in 1993.

Clinical

History

The history helps both in differentiating gastroenteritis from other, often more serious, causes of vomiting and diarrhea in children, and in estimating the degree of dehydration. In some cases, the history can also aid in determining the type of pathogen responsible for the gastroenteritis, though only rarely will this effect management.

• Diarrhea: Duration of diarrhea, the frequency and amount of stools, the time since last episode of diarrhea, and the quality of stools. Frequent, watery stools are more consistent with viral gastroenteritis, while stools with blood or mucous are indicative of a bacterial pathogen. Similarly, a long duration of diarrhea (>14 d) is more consistent with a parasitic or noninfectious cause of diarrhea.
• Vomiting: Duration of vomiting, the amount and quality of vomitus (ie, food contents, blood, bile), and time since the last episode of vomiting. When symptoms of vomiting predominate, one should consider other diseases such as gastroesophageal reflux disease (GERD), gastric outlet (eg, pyloric stenosis) or intestinal obstruction (eg, hernia, intussusception), CNS etiologies, diabetic ketoacidosis, or urinary tract infection. Bilious emesis may represent intestinal obstruction.
• Urine output: Increase or decrease in frequency of urination measured by number of wet diapers, time since last urination, color and concentration of urine, and presence of dysuria. Urine output may be difficult to determine with frequent watery stools.
• Abdominal pain: Location, quality, radiation, severity, and timing of pain, per report of parents and/or child. In general, pain that precedes vomiting and diarrhea is more likely to be due to abdominal pathology other than gastroenteritis.
• Signs of infection: Presence of fever, chills, myalgias, and rash. These symptoms may indicate evidence of systemic infection or sepsis.
• Appearance and behavior: Weight loss, quality of feeding, amount and frequency of feeding, level of thirst, level of alertness, increased malaise, lethargy, or irritability, quality of crying, and presence or absence of tears with crying.
• Antibiotics: History of recent antibiotic use increases the likelihood of Clostridium difficile colitis.
• Travel: History of travel to endemic areas may make prompt consideration of relatively rare organisms, such as parasitic diseases or cholera.

Physical

The physical examination should confirm and clarify the assessment of dehydration and should narrow diagnostic possibilities generated by the history.

• General: Weight, appearance, level of alertness, lethargy, irritability
• HEENT: Presence or absence of tears, dry or moist mucous membranes, sunken eyes, or sunken fontanelle
• Cardiovascular: Heart rate, blood pressure, quality of pulses, perfusion, temperature of skin and distal extremities
• Respiratory: Rate and quality of respirations; the presence of deep, acidotic breathing increases the likelihood of dehydration.
• Abdomen: Abdominal tenderness, guarding, and rebound, bowel sounds. Abdominal tenderness on examination, with or without guarding, should prompt consideration of diseases other than viral gastroenteritis.
• Back: Flank/costovertebral angle (CVA) tenderness increases the likelihood of pyelonephritis.
• Rectal: Quality and color of stool, presence of gross blood or mucous
• Extremities: Capillary refill time, warm or cool extremities
• Skin: Abdominal rash may indicate typhoid fever (infection with Salmonella typhi) while jaundice might make viral or toxic hepatitis more likely.

Causes

Identifying the specific etiologic agent responsible for the acute gastroenteritis rarely changes management. However, it may be helpful to differentiate between viral, bacterial, parasitic, and noninfectious causes of diarrhea.

• By far, viruses remain the most common cause of acute gastroenteritis in children, in both the developed world and the developing world. 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.
  • Rotavirus represents the most important viral pathogen, responsible for up to half of all cases of acute gastroenteritis in developed countries, and 5-20% of cases diarrhea in developing countries.
  • Enteric adenoviruses may be the second most common cause of viral gastroenteritis in developed countries, accounting for 5-20% of pediatric gastroenteritis.
  • Noroviruses (Norwalklike viruses) are responsible for 68-80% of all outbreaks of gastroenteritis, such as food-borne outbreaks, in developed countries.
• In developed countries, bacterial pathogens account for a small portion, perhaps 2-10%, of all cases of pediatric gastroenteritis. 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.
  • In the United States, the most important pathogens, in order of prevalence, are Campylobacter, Salmonella, and Shigella, species and enterohemorrhagic Escherichia coli (EHEC).
  • In developing countries, enterotoxigenic E coli (ETEC) remains the most important bacterial cause of acute gastroenteritis in children, while also causing most cases of traveler's diarrhea in all age groups. Unlike other bacterial causes of gastroenteritis, ETEC is unlikely to cause dysentery.
  • C difficile has emerged as an important cause of antibiotic associated diarrhea in children. Since 50% of neonates and young infants are colonized with C difficile, symptomatic disease is unlikely in children younger than 12 months.
  • Cholera, caused by the organism Vibrio cholerae, leads to severe watery diarrhea and rapid dehydration. It generally occurs in the setting of epidemics due to poor water quality and sanitation.
• Parasites remain yet another source of gastroenteritis in young children, with Giardia and Cryptosporidium species the most common causes in the United States. Parasitic gastroenteritis generally present with watery stools but can be differentiated from viral gastroenteritis by a protracted course or history of travel to endemic areas.

• Search for CME/CE on This Topic »

• Gastroenteritis (Pediatrics: General Medicine)
• Gastroenteritis, Bacterial (Gastroenterology)
• Gastroenteritis, Viral (Gastroenterology)
• Eosinophilic Gastroenteritis (Gastroenterology)

• Pentavalent Rotavirus Vaccine Reduces Gastroenteritis in Children
• American Academy of Pediatrics Updates Guidelines for Use of Rotavirus Vaccine
• ACIP Issues Guidelines for Prevention of Rotavirus Gastroenteritis

• Pediatric Acute Gastroenteritis: Clinical Assessment, Oral Rehydration and Antiemetic Therapy
• RotaTeq: A Three-dose Oral Pentavalent Reassortant Rotavirus Vaccine
• Variation in Pediatric Hospitalists' Use of Proven and Unproven Therapies: A Study from the Pediatric Research in Inpatient Settings (PRIS) Network

• Pediatrics/Neonatal Care Nursing Resource Center
• Growth and Development