What is the treatment for a stomach bug?

Treatment of Stomach Bug (Acute Gastroenteritis)

The primary treatment for a stomach bug is oral rehydration therapy to maintain fluid balance, along with supportive care, as most cases are self-limiting viral infections that resolve within a few days without specific antimicrobial therapy. 1

Assessment and Diagnosis

• Acute gastroenteritis is characterized by a change in stool consistency to loose or liquid and/or increased frequency of defecation (more than 3 times per day), often accompanied by nausea, vomiting, and sometimes fever 2
• Viruses are the most common cause (approximately 70% of cases in children), followed by bacteria and parasites 3, 4
• Diagnostic testing is not needed for mild symptoms that resolve within a week, but should be considered for:
  • Symptoms lasting longer than 7 days 1
  • Severe symptoms including bloody diarrhea 1
  • Recent antibiotic exposure (test for Clostridioides difficile) 4

First-Line Treatment

Rehydration

• Oral rehydration therapy (ORT) is the cornerstone of treatment and is as effective as intravenous therapy for mild to moderate dehydration 1, 3
• For adults, maintenance of good hydration is essential, particularly among the elderly and those on diuretic medications 1
• Children respond well to ORT; hospitalization and IV fluids are only required for severe dehydration or when caregivers cannot provide adequate oral rehydration 1
• Glucose-containing fluids and electrolyte-rich soups are usually sufficient for adults 1

Diet

• Maintain fluid intake during illness 1
• There is controversy about fasting and resumption of solid food:
  • Fasting may be logical if gastroenteritis is associated with nausea and vomiting 1
  • However, early resumption of feeding and solid food intake may encourage net fluid absorption 1
  • For infants, breast milk may have a protective effect, and most can be "fed through" an episode 1

Symptomatic Treatment

Anti-emetics

• Ondansetron has been shown to be effective in reducing gastroenteritis-related vomiting, facilitating ORT, and decreasing hospitalization rates, particularly in children 5, 3
• Bismuth subsalicylate has been shown to reduce the duration of Norwalk virus infection from 27 to 20 hours in adults 1

Anti-diarrheals

• Loperamide is more effective than bismuth subsalicylate for controlling diarrhea, especially in traveler's diarrhea caused by E. coli 1
• However, antimotility agents should be used with caution, particularly in cases of bloody diarrhea or suspected invasive bacterial infection 1

Antimicrobial Therapy

• Antimicrobial therapy is generally NOT recommended for most cases of acute gastroenteritis 1
• Empiric antimicrobial therapy should only be considered in specific situations:
  • Infants <3 months of age with suspected bacterial infection 1
  • Immunocompromised patients with severe illness and bloody diarrhea 1
  • Patients with fever, abdominal pain, bloody diarrhea, and symptoms of bacillary dysentery (presumptively due to Shigella) 1
  • Recent international travelers with high fever (≥38.5°C) and/or signs of sepsis 1
• When indicated, empiric antimicrobial therapy for adults should be either a fluoroquinolone (e.g., ciprofloxacin) or azithromycin, depending on local susceptibility patterns and travel history 1

Special Considerations

Children

• For children requiring antimicrobial therapy, options include:
  • Third-generation cephalosporin for infants <3 months of age 1
  • Azithromycin for older children, depending on local susceptibility patterns 1

Elderly and Immunocompromised

• These populations are at higher risk for dehydration and complications 1
• Lower threshold for hospitalization and more aggressive rehydration may be warranted 1
• Consider empiric antibacterial treatment in immunocompromised people with severe illness 1

Prevention of Transmission

• Thorough handwashing with soap is necessary to control the spread of enteric pathogens 1
• Detergents should be used for laundering fecally contaminated linens and clothing 1
• Thorough cleaning of environmental surfaces is required to control spread of viral agents 1

Follow-up

• Follow-up testing is not recommended in most people after resolution of diarrhea 1
• Consider clinical and laboratory reevaluation for those who do not respond to initial therapy 1
• For symptoms lasting 14 or more days without identified cause, consider non-infectious conditions including irritable bowel syndrome and inflammatory bowel disease 1

Common Pitfalls to Avoid

• Unnecessary use of antibiotics can lead to increased bacterial resistance, C. difficile colitis, and other complications 1
• Underuse of oral rehydration therapy due to vomiting; consider appropriate anti-emetics to facilitate ORT 3
• Failure to recognize dehydration, particularly in vulnerable populations like children and the elderly 1