What is the treatment for bacterial gastroenteritis?

Treatment for Bacterial Gastroenteritis

The primary treatment for bacterial gastroenteritis is oral rehydration therapy (ORT) with reduced osmolarity oral rehydration solution, which should be initiated immediately to correct and prevent dehydration, while antimicrobial therapy is reserved for specific indications and pathogens. 1

Rehydration Therapy

• Reduced osmolarity oral rehydration solution (ORS) is the first-line therapy for mild to moderate dehydration in both children and adults with bacterial gastroenteritis 1
• For patients with severe dehydration, shock, altered mental status, or ileus, isotonic intravenous fluids (lactated Ringer's or normal saline) should be administered until clinical improvement occurs 1
• Nasogastric administration of ORS may be considered for patients with moderate dehydration who cannot tolerate oral intake 1
• Once rehydrated, maintenance fluids should be provided and ongoing stool losses replaced with ORS until diarrhea resolves 1
• Age-appropriate diet should be resumed during or immediately after rehydration is completed 1

Antimicrobial Therapy

When to Use Antibiotics

Empiric antimicrobial therapy is generally not recommended for most cases of bacterial gastroenteritis 1, 2, except in the following situations:

• Infants under 3 months of age with suspected bacterial etiology 1
• Immunocompromised patients with severe illness and bloody diarrhea 1
• Patients with fever documented in a 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 high fever (≥38.5°C) and/or signs of sepsis 1
• Clinical features of enteric fever 1

Choice of Antimicrobial Agents

When indicated, antimicrobial therapy should be guided by:

• For adults: Fluoroquinolones (e.g., ciprofloxacin) or azithromycin, depending on local susceptibility patterns and travel history 1
• For children: Third-generation cephalosporin for infants <3 months or those with neurologic involvement, or azithromycin 1
• For specific pathogens:
  • Campylobacter: Azithromycin is preferred due to increasing fluoroquinolone resistance 1
  • Shigella: Ciprofloxacin or another fluoroquinolone; azithromycin as an alternative 1
  • Salmonella: Ciprofloxacin, TMP-SMX, or amoxicillin based on susceptibility testing 1
  • Avoid antimicrobial therapy for STEC O157 and other Shiga toxin 2-producing E. coli 1

Supportive Care

• Antimotility drugs (e.g., loperamide) should not be given to children under 18 years with acute diarrhea 1
• Loperamide may be given to immunocompetent adults with acute watery diarrhea but should be avoided in cases of inflammatory diarrhea or diarrhea with fever 1
• Antiemetics (e.g., ondansetron) may be given to facilitate oral rehydration in children over 4 years and adolescents with vomiting 1, 3
• Probiotic preparations may be offered to reduce symptom severity and duration in immunocompetent patients 1
• Zinc supplementation reduces diarrhea duration in children 6 months to 5 years of age in countries with high zinc deficiency prevalence or in children with signs of malnutrition 1

Infection Control Measures

• Hand hygiene should be performed after using the toilet, changing diapers, before and after preparing food, and before eating 1
• Use of gloves, gowns, and proper hand hygiene is essential when caring for patients with diarrhea 1
• Asymptomatic contacts of people with bacterial gastroenteritis do not need treatment but should follow appropriate infection prevention measures 1

Monitoring and Follow-up

• Continue monitoring hydration status until symptoms resolve 1
• Antimicrobial therapy should be modified or discontinued when a specific pathogen is identified from diagnostic tests 1
• For persistent symptoms, reassessment of fluid and electrolyte balance, nutritional status, and antimicrobial therapy is recommended 1, 2

Cautions and Pitfalls

• Avoid antimotility agents in children under 18 years and in patients with bloody diarrhea or fever due to risk of complications 1
• Avoid antibiotics for STEC O157 infections as they may increase the risk of hemolytic uremic syndrome 1
• Do not delay rehydration while waiting for diagnostic test results 1, 4
• Recognize that empiric antibiotic treatment often does not follow clinical practice guidelines, while targeted treatment based on diagnostic testing shows better compliance 5