Gastroenteritis Treatment Guidelines

Etiology and Epidemiology

• Rotavirus is the most common cause of gastroenteritis in children <5 years before vaccine introduction, now less common due to vaccination, according to the Centers for Disease Control and Prevention 1
• Norovirus is the leading pathogen causing gastroenteritis in the US, responsible for 58% of cases, as reported by the Infectious Diseases Society of America 2
• Salmonella is the leading bacterial cause of gastroenteritis, responsible for 11% of cases and 35% of hospitalizations, according to the Infectious Diseases Society of America 2
• Immunocompromised patients are at higher risk of severe, prolonged, and even fatal rotavirus gastroenteritis, as noted by the Centers for Disease Control and Prevention 1

Clinical Presentation

• Gastroenteritis typically presents with abrupt onset, often with vomiting preceding diarrhea, and can include fever, with up to one-third of patients having a temperature >102°F (>39°C) 1
• Shigella/Dysentery is characterized by frequent scant bloody stools, fever, abdominal cramps, and tenesmus, as described by the Infectious Diseases Society of America 2
• Salmonella infections often present with fever, abdominal pain, and diarrhea, which may be bloody, according to the Infectious Diseases Society of America 2

Severity Assessment

• The severity of gastroenteritis can be assessed using the following criteria:

2

• Dehydration severity can also be categorized as:

2

Treatment

• Oral rehydration solution (ORS) is the first-line treatment for mild to moderate dehydration, with the American Academy of Pediatrics recommending 50-100 mL/kg over 3-4 hours for children and 2-4 L of ORS for adults 2, 3, 4
• Empiric antimicrobial therapy is not recommended except in specific situations, such as infants <3 months with suspected bacterial etiology, immunocompromised patients with severe illness and bloody diarrhea, and patients with signs of sepsis, as stated by the Infectious Diseases Society of America 2
• When indicated, recommended antimicrobials include fluoroquinolone (e.g., ciprofloxacin) or azithromycin for adults, and third-generation cephalosporin (infants <3 months) or azithromycin for children, according to the Infectious Diseases Society of America 2
• Ondansetron may be given to children >4 years and adolescents to facilitate oral rehydration when vomiting is significant, and has been shown to reduce the need for hospitalization and IV fluids in children, according to the American Academy of Pediatrics 3, 2
• Loperamide is contraindicated in children <18 years with acute diarrhea, and may be used in immunocompetent adults with acute watery diarrhea, but should be avoided in inflammatory diarrhea, bloody diarrhea, or fever, as recommended by the Infectious Diseases Society of America 3, 2
• Antimicrobial therapy is not routinely recommended for most cases of gastroenteritis, except in specific situations such as infants <3 months with suspected bacterial etiology, immunocompromised patients with severe illness and bloody diarrhea, patients with fever >38.5°C, recent international travel, and signs of sepsis, or confirmed bacterial pathogens requiring treatment, according to the American Gastroenterological Association 2, 5
• Indications for intravenous fluids include severe dehydration, shock, altered mental status, ileus, or failure of ORT, and isotonic fluids (lactated Ringer's or normal saline) are recommended, according to the Infectious Diseases Society of America 3

Prevention

• Hand hygiene is critical after using the toilet, changing diapers, before/after food preparation, and after handling garbage, and proper cleaning of environmental surfaces and appropriate food safety practices are essential to avoid cross-contamination, according to the Centers for Disease Control and Prevention 3, 1, 2
• Vaccination, such as the rotavirus vaccine, has reduced infections by up to 90% in children, as reported by the Centers for Disease Control and Prevention 1
• Food safety practices, including proper cooking and storage of food, can help prevent gastroenteritis, as recommended by the Centers for Disease Control and Prevention 1
• Probiotics may reduce symptom severity and duration in immunocompetent adults and children, according to the American College of Gastroenterology 3
• Zinc supplementation is beneficial for children 6 months to 5 years in countries with high zinc deficiency prevalence, as recommended by the World Health Organization 3
• Patients on anticoagulation require special attention to medication interactions, and close monitoring for signs of dehydration is necessary in the elderly, as recommended by the American Gastroenterological Association 6
• The American Academy of Pediatrics recommends providing adequate caregiver education about continued hydration at home, and avoiding common pitfalls such as using ondansetron as a substitute for rehydration therapy, administering loperamide to children, delaying reintroduction of normal diet, and overlooking the need for IV fluids in severely dehydrated patients 2
• Vulnerable populations (very young, elderly) are at higher risk of dehydration due to higher body surface-to-weight ratio, higher metabolic rate, and dependence on others for fluid intake, and oral rehydration is as effective as IV rehydration for preventing hospitalization in these populations, according to the American Gastroenterological Association 4
• Older adults are more susceptible to complications from dehydration and require close monitoring for dehydration signs (dry mouth, decreased urination, dizziness, confusion), according to the American Geriatrics Society 3
• Early refeeding is recommended during or immediately after rehydration, and breastfeeding should continue throughout the diarrheal episode in infants and children, as suggested by the American Academy of Pediatrics 3
• A regular diet should be resumed quickly, and fasting for 24 hours is not beneficial, according to the American Gastroenterological Association 2
• The World Health Organization recommends continuing breastfeeding throughout the diarrheal episode if applicable, and resuming age-appropriate diet during or immediately after rehydration 2