What is the treatment for acute gastroenteritis?

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Treatment of Acute Gastroenteritis

The mainstay of treatment for acute gastroenteritis is oral rehydration therapy (ORT), which should be the first-line approach for mild to moderate dehydration in both children and adults. 1

Assessment of Hydration Status

  • Evaluate hydration status through physical examination, which is the most reliable method to determine severity of dehydration 2
  • Look for specific signs of dehydration: decreased skin turgor, dry mucous membranes, sunken eyes, altered mental status, tachycardia, and decreased urine output 1
  • Categorize dehydration as mild, moderate, or severe based on clinical presentation 1

Rehydration Therapy

Mild to Moderate Dehydration

  • Provide oral rehydration solution (ORS) as first-line therapy 1
    • For infants and children: 50-100 mL/kg over 3-4 hours 1
    • For adolescents and adults: 2-4 L of ORS 1
  • Use commercially available low-osmolarity ORS (e.g., Pedialyte, CeraLyte) 1
  • Avoid apple juice, Gatorade, and commercial soft drinks as they are not appropriate for rehydration 1
  • For children who refuse ORS, nasogastric administration may be considered 1

Severe Dehydration

  • Administer isotonic intravenous fluids (lactated Ringer's or normal saline) 1
  • Continue IV rehydration until pulse, perfusion, and mental status normalize 1
  • Once stabilized, transition to oral rehydration to replace remaining deficit 1

Maintenance and Ongoing Losses

  • Replace ongoing losses with ORS until diarrhea and vomiting resolve 1
  • For children <10 kg: 60-120 mL ORS for each diarrheal stool/vomiting episode (up to ~500 mL/day) 1
  • For children >10 kg: 120-240 mL ORS for each diarrheal stool/vomiting episode (up to ~1 L/day) 1
  • For adolescents and adults: Ad libitum intake up to ~2 L/day 1

Nutritional Management

  • Continue breastfeeding throughout the diarrheal episode in infants 1
  • Resume age-appropriate diet during or immediately after rehydration 1
  • Avoid fasting or withholding food for 24 hours as this does not improve outcomes 1
  • The BRAT (bananas, rice, applesauce, toast) diet has limited supporting evidence 1

Pharmacological Management

Antiemetics

  • Consider ondansetron in children >4 years and adolescents with significant vomiting to facilitate oral rehydration 1, 3
  • Ondansetron has been shown to reduce vomiting episodes, decrease need for IV fluids, and reduce hospitalization rates 1, 4
  • Antiemetics should only be used after adequate hydration has been initiated, not as a substitute for fluid therapy 1

Antimotility Agents

  • Loperamide may be given to immunocompetent adults with acute watery diarrhea 1
  • Loperamide should NOT be given to children <18 years of age 1
  • Avoid antimotility agents in cases of inflammatory diarrhea, diarrhea with fever, or suspected toxic megacolon 1

Probiotics and Supplements

  • Probiotic preparations may reduce symptom severity and duration in immunocompetent patients 1
  • Zinc supplementation may be beneficial for children 6 months to 5 years in countries with high prevalence of zinc deficiency 1

Prevention Measures

  • Practice proper hand hygiene after using toilet, changing diapers, before/after food preparation, and after handling animals 1
  • Use infection control measures including gloves, gowns, and hand hygiene with soap and water or alcohol-based sanitizers when caring for patients with diarrhea 1

Common Pitfalls to Avoid

  • Delaying oral rehydration in favor of IV fluids when ORT would be sufficient 5
  • Using inappropriate fluids for rehydration (sports drinks, sodas, undiluted fruit juices) 1
  • Withholding food during acute gastroenteritis, which can prolong recovery 1
  • Prescribing antimotility agents for children, which can lead to serious complications 1
  • Failing to replace ongoing fluid losses during the illness 1

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Gastroenteritis in Children.

American family physician, 2019

Research

Acute gastroenteritis: from guidelines to real life.

Clinical and experimental gastroenterology, 2010

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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