What is the recommended treatment for a patient presenting with viral gastroenteritis (stomach flu)?

Treatment of Viral Gastroenteritis (Stomach Flu)

The cornerstone of treatment for viral gastroenteritis is oral rehydration therapy (ORT) using reduced osmolarity oral rehydration solution (ORS), which is as effective as intravenous fluids for mild-to-moderate dehydration and should be the first-line therapy for all age groups. 1

Primary Treatment Approach

Rehydration Strategy

• Reduced osmolarity ORS is the first-line therapy for mild to moderate dehydration in infants, children, and adults with acute diarrhea from any cause 1
• ORT is as effective as intravenous therapy for correcting dehydration, with the added benefits of shorter hospital stays and lower costs 2
• For patients who cannot tolerate oral intake, nasogastric administration of ORS may be considered in those with moderate dehydration and normal mental status 1

When to Escalate to Intravenous Fluids

• Use isotonic intravenous fluids (lactated Ringer's or normal saline) only when there is 1:

  • Severe dehydration with shock
  • Altered mental status
  • Failure of ORS therapy
  • Ileus
  • Ketonemia requiring initial IV hydration to enable tolerance of oral rehydration

• Continue IV rehydration until pulse, perfusion, and mental status normalize, the patient awakens, has no aspiration risk, and shows no evidence of ileus 1

Antimicrobial Therapy: When NOT to Use Antibiotics

Empiric antimicrobial therapy is NOT recommended for viral gastroenteritis, as it is a self-limited illness requiring only supportive care 1

Critical Distinction: Viral vs. Bacterial

• Do not give antibiotics for typical viral gastroenteritis presenting with watery (non-bloody) diarrhea, even with fever 1
• Antibiotics are only indicated for specific bacterial infections with bloody diarrhea and specific clinical features (fever documented in medical setting, abdominal pain, bacillary dysentery) 1

Symptomatic Management

Supportive Care Measures

• Maintain adequate hydration as the primary goal, particularly in elderly patients and those on diuretic medications 1
• Continue normal feeding in children; breast milk may have protective effects and most infants can be "fed through" an episode 1
• Bismuth subsalicylate may reduce symptom duration modestly (from 27 to 20 hours in Norwalk virus infection) 1

Antiemetics

• Antiemetics can improve tolerance of oral rehydration solution and decrease the need for IV fluids and hospitalization when used appropriately 3

Duration and Expected Course

• Viral gastroenteritis is typically self-limited, lasting a few days with virus replication restricted to the gut mucosa 1
• The main risk is dehydration and electrolyte imbalance, not the infection itself 1

Red Flags Requiring Further Evaluation

When to Suspect Bacterial Infection Instead

• Bloody diarrhea is not typical of viral gastroenteritis and requires stool culture and consideration of bacterial pathogens 4, 5
• Fever persisting beyond 3 days despite supportive care warrants investigation for bacterial causes 5
• Signs of sepsis, severe abdominal pain with tenesmus, or recent international travel with high fever (≥38.5°C) suggest bacterial etiology requiring empiric antibiotics 1

Specific Populations Requiring Closer Monitoring

• Infants under 3 months with suspected bacterial etiology require empiric third-generation cephalosporin 1
• Immunocompromised patients with severe illness and bloody diarrhea should receive empiric antibacterial treatment 1
• Malnourished individuals are at higher risk for the cycle of diarrhea worsening nutritional status 1

Common Pitfalls to Avoid

• Do not withhold fluids or food unnecessarily; early refeeding is beneficial 1
• Do not use antibiotics for STEC (Shiga toxin-producing E. coli) infections, especially O157 strains, as this increases risk of hemolytic uremic syndrome 1
• Do not treat asymptomatic contacts of patients with diarrhea 1
• Do not assume special handwashing products are needed; vigorous handwashing with regular soap is sufficient for infection control 1

Infection Control Measures

• Vigorous handwashing with soap at appropriate intervals is necessary to control spread of all enteric pathogens 1
• Thorough cleaning of environmental surfaces is required as rotavirus can survive for several days on nonporous materials 1
• Detergents should be used for laundering fecally contaminated linens and clothing 1
• Ill persons should be separated from well persons until at least 2 days after resolution of symptoms 1