What treatment can be given for gastroenteritis?

Treatment of Gastroenteritis

Oral rehydration solution (ORS) is the first-line treatment for gastroenteritis with mild to moderate dehydration, and should be initiated immediately without waiting for diagnostic testing. 1

Rehydration Strategy

Assessment of Dehydration Severity

• Evaluate hydration status through clinical signs: skin turgor, mental status, mucous membrane moisture, capillary refill, and vital signs 1
• Categorize dehydration as:
  • Mild (3-5%): Treat with ORS at home 1
  • Moderate (6-9%): Administer ORS at 100 mL/kg over 2-4 hours 1
  • Severe (≥10%): Requires intravenous rehydration with isotonic fluids (lactated Ringer's or normal saline) 1

Oral Rehydration Therapy

• Use low-osmolarity ORS formulations rather than sports drinks, apple juice, or other high-sugar beverages, as simple sugars can worsen diarrhea through osmotic effects 1
• For persistent vomiting, start with small volumes using a syringe or medicine dropper, gradually increasing as tolerated 1
• Replace ongoing losses: give 10 mL/kg ORS for each watery stool and 2 mL/kg for each vomiting episode 1
• Nasogastric administration may be considered for patients who cannot tolerate oral intake or refuse to drink adequately 1

Intravenous Rehydration

• Reserve IV fluids for: severe dehydration, shock, altered mental status, failure of oral rehydration therapy, or ileus 1
• Continue IV rehydration until pulse, perfusion, and mental status normalize, then transition to ORS 1

Nutritional Management

• Resume age-appropriate diet during or immediately after rehydration—early refeeding is recommended rather than fasting or restrictive diets 1
• Continue breastfeeding in infants throughout the diarrheal episode 1
• Avoid foods high in simple sugars (soft drinks, undiluted apple juice) as they exacerbate diarrhea 1

Pharmacological Management

Antiemetics

• Ondansetron may be given to children >4 years and adolescents to facilitate oral rehydration when vomiting is significant 1, 2
• Ondansetron works by blocking serotonin at the chemoreceptor trigger zone and does not have antimotility effects 2
• Contraindications for ondansetron: inflammatory diarrhea (suspected or confirmed), bloody diarrhea with fever (risk of toxic megacolon), and children with cardiac disease (QT prolongation risk) 2

Antimotility Agents

• Loperamide is contraindicated in children <18 years with acute diarrhea 1, 3
• In immunocompetent adults, loperamide may be given only after adequate hydration and only for acute watery diarrhea 1
• The FDA warns that loperamide can cause serious cardiac adverse reactions including QT prolongation, Torsades de Pointes, and sudden death, especially at higher than recommended doses 3
• Never use loperamide in: bloody diarrhea, suspected inflammatory colitis, pediatric patients <2 years (contraindicated due to respiratory depression and cardiac risks), or when combined with QT-prolonging drugs 3
• Maximum adult dose is 16 mg/day (eight 2 mg capsules); avoid exceeding this dose 3

Other Medications

• Antimotility agents, adsorbents, antisecretory drugs, and toxin binders should not be used as they do not reduce diarrhea volume or duration 1
• Probiotics may reduce symptom severity and duration in both adults and children 1
• Zinc supplementation reduces diarrhea duration in children 6 months to 5 years in areas with high zinc deficiency or malnutrition 1
• Antimicrobial agents have limited usefulness since viral agents are the predominant cause; consider antibiotics only for bloody diarrhea, recent antibiotic use (test for C. difficile), exposure to specific pathogens, recent foreign travel, or immunodeficiency 1

Infection Control

• Practice proper hand hygiene after toilet use, diaper changes, before food preparation and eating, and after handling soiled items 1
• Use gloves and gowns when caring for people with diarrhea 1
• Clean and disinfect contaminated surfaces promptly 1
• Separate ill persons from well persons until at least 2 days after symptom resolution 1

Critical Pitfalls to Avoid

• Do not delay rehydration while awaiting diagnostic testing—begin ORS immediately 1
• Do not use sports drinks or apple juice as primary rehydration solutions for moderate to severe dehydration 1
• Do not give antimotility drugs to children or in cases of bloody diarrhea due to risk of toxic megacolon and other serious complications 1, 3
• Do not restrict diet unnecessarily during or after rehydration 1
• Do not rely on antidiarrheal agents like metamizole, as this shifts focus away from appropriate fluid, electrolyte, and nutritional therapy 1