What is the treatment for infectious gastroenteritis?

Treatment of Infectious Gastroenteritis

The cornerstone of treatment for infectious gastroenteritis is oral rehydration therapy (ORT) with reduced osmolarity oral rehydration solution (ORS) as the first-line approach for mild to moderate dehydration in both children and adults. 1, 2

Assessment and Rehydration

• Evaluate hydration status through physical examination looking for specific signs including decreased skin turgor, dry mucous membranes, sunken eyes, altered mental status, tachycardia, and decreased urine output 1
• Categorize dehydration as:
  • Mild: <4% body weight loss
  • Moderate: 4-6% body weight loss
  • Severe: >6% body weight loss 1

Rehydration Protocol

• For mild to moderate dehydration:
  • Provide oral rehydration solution (ORS) as first-line therapy 2, 1
  • Dosage: 50-100 mL/kg over 3-4 hours for infants and children; 2-4 L for adolescents and adults 1
  • Use commercially available low-osmolarity ORS (e.g., Pedialyte, CeraLyte) 1, 3
  • Avoid apple juice, sports drinks like Gatorade, and commercial soft drinks as primary rehydration solutions as they may have inappropriate electrolyte and sugar content 1
• For patients who cannot tolerate oral intake:
  • Consider nasogastric administration of ORS for children with normal mental status who refuse to drink 2, 1
• For severe dehydration:
  • Administer isotonic intravenous fluids (lactated Ringer's or normal saline) 2, 1
  • Continue IV rehydration until pulse, perfusion, and mental status normalize 2
  • Transition to oral rehydration once the patient awakens and has no risk factors for aspiration 2

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 prolonged periods as this does not improve outcomes and may worsen nutritional status 2, 1
• Avoid foods high in simple sugars (soft drinks, undiluted apple juice, Jell-O, presweetened cereals) which can exacerbate diarrhea through osmotic effects 2
• Avoid foods high in fat as they may delay gastric emptying 2

Pharmacological Management

Antimicrobial Therapy

• In immunocompetent children and adults, empiric antimicrobial therapy for infectious gastroenteritis is generally not recommended 2, 4

• Exceptions where empiric antimicrobial therapy should be considered:

  • Infants <3 months of age with suspected bacterial etiology 2
  • Patients with fever documented in a medical setting, abdominal pain, bloody diarrhea, and bacillary dysentery presumptively due to Shigella 2
  • Recent international travelers with fever ≥38.5°C and/or signs of sepsis 2
  • Immunocompromised patients with severe illness and bloody diarrhea 2
  • Patients with clinical features of sepsis who are suspected of having enteric fever 2

• When antimicrobial therapy is indicated:

  • For adults: fluoroquinolone (e.g., ciprofloxacin) or azithromycin, depending on local susceptibility patterns and travel history 2
  • For children: third-generation cephalosporin for infants <3 months of age and others with neurologic involvement, or azithromycin 2
  • Avoid antimicrobial therapy for STEC O157 and other STEC that produce Shiga toxin 2 as it may increase the risk of hemolytic uremic syndrome 2

Symptomatic Medications

• Antiemetics:

  • Consider ondansetron in children >4 years and adolescents with significant vomiting to facilitate oral rehydration (0.15 mg/kg per dose) 1, 5
  • Ondansetron can increase the success rate of ORT and minimize the need for IV therapy and hospitalization 5, 6

• Antimotility agents:

  • Loperamide may be given to immunocompetent adults with acute watery diarrhea (4 mg initially, followed by 2 mg after each loose stool) 1
  • Avoid antimotility agents in cases of bloody diarrhea, diarrhea with fever, or suspected toxic megacolon 2, 1
  • Antiperistaltic drugs should be discontinued if symptoms persist beyond 48 hours 2
  • Antimotility agents are not recommended for children 2

Special Populations

Immunocompromised Patients

• Consider empiric antibacterial treatment in immunocompromised people with severe illness and bloody diarrhea 2
• More aggressive diagnostic workup and treatment may be needed 2

Pregnant Women

• Pregnant women with Salmonella gastroenteritis should receive treatment to prevent extraintestinal spread 2
• Choices for treatment include ampicillin, cefotaxime, ceftriaxone, or TMP-SMZ 2
• Avoid fluoroquinolones during pregnancy 2

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 when caring for patients with diarrhea 1
• Asymptomatic contacts of people with bloody diarrhea should not be offered empiric treatment but should follow appropriate infection prevention measures 2

Follow-up

• Reassess fluid and electrolyte balance, nutritional status, and optimal dose and duration of antimicrobial therapy in people with persistent symptoms 2
• Consider noninfectious conditions, including inflammatory bowel disease and irritable bowel syndrome, in people with symptoms lasting 14 or more days 2