What is the treatment for gastroenteritis?

Treatment of Gastroenteritis

Oral rehydration solution (ORS) is the first-line treatment for mild to moderate dehydration in gastroenteritis, with intravenous fluids reserved only for severe dehydration, shock, altered mental status, or failure of oral rehydration. 1, 2

Initial Assessment and Hydration Status

Assess dehydration severity through clinical signs rather than laboratory tests alone 2:

• Skin turgor, mental status, mucous membrane moisture, capillary refill time, and urine output should guide your assessment 2
• Categorize as mild (3-5% body weight loss), moderate (6-9% body weight loss), or severe (≥10% body weight loss) 2, 3

Rehydration Strategy by Severity

Mild to Moderate Dehydration

Administer ORS as first-line therapy until clinical dehydration is corrected 1, 2:

• Infants and children: 50-100 mL/kg over 3-4 hours 2
• Adolescents and adults: 2-4 L over 3-4 hours 2
• Use small, frequent volumes (5-10 mL every 1-2 minutes) via spoon or syringe to prevent triggering vomiting 3, 4
• Continue ORS to replace ongoing losses: 10 mL/kg for each watery stool and 2 mL/kg for each vomiting episode 3
• Nasogastric administration may be considered if the patient cannot tolerate oral intake 3

Severe Dehydration

Administer isotonic intravenous fluids (lactated Ringer's or normal saline) at 20 mL/kg over 30 minutes 1, 2:

• Continue IV rehydration until pulse, perfusion, and mental status normalize 1, 2
• Transition to ORS to replace remaining deficit once the patient improves 1, 3
• IV therapy is also indicated for shock, altered mental status, failure of ORS therapy, or ileus 1, 3

Nutritional Management

Resume age-appropriate diet during or immediately after rehydration is completed 1, 2:

• Continue breastfeeding throughout the diarrheal episode in infants 1, 3
• Early refeeding reduces severity and duration of illness 3
• Avoid restrictive diets or prolonged fasting 3

Pharmacological Management

Antiemetics

Ondansetron (0.15 mg/kg per dose, maximum 16 mg) may be given to children >4 years and adolescents with significant vomiting to facilitate oral rehydration 1, 2, 4:

• This is an adjunctive treatment only, not a substitute for fluid and electrolyte therapy 4
• Exercise caution in children with heart disease due to potential QT prolongation 4
• Avoid in suspected inflammatory diarrhea or diarrhea with fever 4

Antimotility Agents

Loperamide should NOT be given to children <18 years with acute diarrhea 1, 2:

• May be given to immunocompetent adults with acute watery diarrhea once adequately hydrated (4 mg initially, then 2 mg after each loose stool) 2, 3
• Avoid at any age in suspected inflammatory diarrhea, bloody diarrhea, or fever due to risk of toxic megacolon 1

Adjunctive Therapies

Probiotics may reduce symptom severity and duration in immunocompetent adults and children 1, 2:

• Specific organism selection should be guided by literature and manufacturer guidance 1

Zinc supplementation (10-20 mg daily) reduces diarrhea duration in children 6 months to 5 years in areas with high zinc deficiency prevalence or in malnourished children 1, 2:

• This recommendation is particularly relevant in developing countries 1

Antimicrobial Therapy

Empiric antimicrobial therapy is NOT routinely recommended for most cases of gastroenteritis 3:

• Consider only for bloody diarrhea with fever, abdominal pain, and bacillary dysentery in ill immunocompetent patients 2
• Use fluoroquinolone (ciprofloxacin) or azithromycin depending on local susceptibility patterns and travel history 2
• Infants <3 months with suspected bacterial etiology should receive a third-generation cephalosporin 2

Infection Control Measures

Practice proper hand hygiene after using the toilet, changing diapers, before and after food preparation, and before eating 1, 2:

• Use gloves and gowns when caring for people with diarrhea 1, 3
• Clean and disinfect contaminated surfaces promptly 3
• Hand hygiene with soap and water is necessary, as some commercial handwashing preparations are ineffective against rotavirus 1

Critical Pitfalls to Avoid

Do not delay rehydration while awaiting diagnostic testing - initiate therapy promptly based on clinical assessment 3:

• Do not use sports drinks or apple juice as primary rehydration solutions for moderate to severe dehydration 3, 4
• Do not administer antimotility drugs to children or in cases of bloody diarrhea 1, 3
• Do not unnecessarily restrict diet during or after rehydration 3
• Do not underestimate dehydration in elderly patients, who may not manifest classic signs and have higher mortality risk 3
• Do not use ondansetron as first-line treatment in children under 4 years - focus on proper ORS administration technique instead 4