When should empiric antibiotics be given for diarrhea?

When to Give Empiric Antibiotics for Diarrhea

Empiric antibiotics for diarrhea should generally be avoided in most cases of acute watery diarrhea and should only be given in specific clinical scenarios with high risk of complications or specific presentations suggesting bacterial etiology. 1

Indications for Empiric Antibiotics in Bloody Diarrhea

• Empiric antimicrobial therapy is NOT recommended for most cases of bloody diarrhea while waiting for diagnostic results 1

• Empiric antibiotics are indicated ONLY in the following situations:

  • Infants less than 3 months of age with suspected bacterial etiology 1

  • Patients with fever (documented in medical setting), abdominal pain, bloody diarrhea, and bacillary dysentery (frequent scant bloody stools, fever, abdominal cramps, tenesmus) presumptively due to Shigella 1

  • Recent international travelers with temperatures ≥38.5°C and/or signs of sepsis 1

  • Immunocompromised patients with severe illness and bloody diarrhea 1

  • Patients with clinical features of sepsis who are suspected of having enteric fever 1

Indications for Empiric Antibiotics in Watery Diarrhea

• In most people with acute watery diarrhea without recent international travel, empiric antimicrobial therapy is NOT recommended 1

• Exceptions where empiric antibiotics may be considered:

  • Immunocompromised patients 1, 2

  • Young infants who appear ill 1

  • Severely ill patients with high stool frequency, fever, or significant comorbidities 2

• Avoid empiric antibiotics in patients with persistent watery diarrhea lasting 14 days or more (consider non-infectious causes) 1

Contraindications for Empiric Antibiotics

• Avoid antibiotics in infections attributed to STEC O157 and other Shiga toxin 2-producing E. coli as antibiotics may increase the risk of hemolytic uremic syndrome 1

• Avoid antimotility agents in patients with bloody diarrhea, STEC infections, C. difficile infections, or severe colitis 2

• Do not give empiric antibiotics to asymptomatic contacts of patients with either bloody or watery diarrhea 1

Choice of Empiric Antibiotics When Indicated

• For adults: Either a fluoroquinolone (ciprofloxacin) or azithromycin, depending on local susceptibility patterns and travel history 1, 3

• For children:

  • Third-generation cephalosporin for infants <3 months of age and others with neurologic involvement 1
  • Azithromycin for other children, based on local susceptibility patterns and travel history 1, 3

• For C. difficile-associated diarrhea: Use fidaxomicin or vancomycin (not empiric therapy, but targeted once C. difficile is confirmed) 4

Management Principles

• Modify or discontinue antimicrobial treatment when a clinically plausible organism is identified 1

• Rehydration is the cornerstone of management for all patients with diarrhea:

  • Use reduced osmolarity oral rehydration solution (ORS) for mild to moderate dehydration 1
  • Use intravenous fluids for severe dehydration, shock, altered mental status, or ileus 1

• Reassess patients who do not respond to initial therapy for:

  • Non-infectious conditions (IBD, IBS, lactose intolerance) 1
  • Fluid and electrolyte balance 1
  • Optimal dose and duration of antimicrobial therapy 1

Common Pitfalls to Avoid

• Overuse of empiric antibiotics in uncomplicated diarrhea, which can lead to antimicrobial resistance 2

• Failure to recognize the risk of hemolytic uremic syndrome when using antibiotics for STEC infections 1

• Neglecting rehydration therapy while focusing on antimicrobial treatment 1

• Not considering C. difficile in patients with recent antibiotic exposure who develop diarrhea 5

• Using fluoroquinolones empirically in areas with high resistance rates, particularly for Campylobacter infections 3