Treatment for Bacterial Gastroenteritis

Rehydration Therapy

• 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, as recommended by the Infectious Diseases Society of America 1, 2
• Reduced osmolarity oral rehydration solution (ORS) is the first-line therapy for mild to moderate dehydration in both children and adults with bacterial gastroenteritis, according to the Infectious Diseases Society of America 1, 3
• 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, as recommended by the Infectious Diseases Society of America 1, 2
• Nasogastric administration of ORS may be considered for patients with moderate dehydration who cannot tolerate oral intake, as suggested by the Infectious Diseases Society of America 2, 3
• Once rehydrated, maintenance fluids should be provided and ongoing stool losses replaced with ORS until diarrhea resolves, according to the Infectious Diseases Society of America 1, 4
• Age-appropriate diet should be resumed during or immediately after rehydration is completed, as recommended by the Infectious Diseases Society of America 1, 3

Antimicrobial Therapy

• Empiric antimicrobial therapy is generally not recommended for most cases of bacterial gastroenteritis, except in specific situations, such as infants under 3 months of age with suspected bacterial etiology, immunocompromised patients with severe illness and bloody diarrhea, and patients with fever, abdominal pain, bloody diarrhea, and bacillary dysentery, as recommended by the Infectious Diseases Society of America 5, 6
• When indicated, antimicrobial therapy should be guided by local susceptibility patterns and travel history, with fluoroquinolones (e.g., ciprofloxacin) or azithromycin recommended for adults, and third-generation cephalosporin or azithromycin recommended for children, according to the Infectious Diseases Society of America 5, 7
• Specific antimicrobial agents are recommended for specific pathogens, including azithromycin for Campylobacter, ciprofloxacin or another fluoroquinolone for Shigella, and ciprofloxacin, TMP-SMX, or amoxicillin for Salmonella, as recommended by the Infectious Diseases Society of America 7

Supportive Care

• Antimotility drugs (e.g., loperamide) should not be given to children under 18 years with acute diarrhea, as recommended by the Centers for Disease Control and Prevention 1, 8
• Loperamide may be given to immunocompetent adults with acute watery diarrhea, but should be avoided in cases of inflammatory diarrhea or diarrhea with fever, according to the Infectious Diseases Society of America 1, 3
• Antiemetics (e.g., ondansetron) may be given to facilitate oral rehydration in children over 4 years and adolescents with vomiting, as recommended by the Infectious Diseases Society of America 1
• Probiotic preparations may be offered to reduce symptom severity and duration in immunocompetent patients, according to the Infectious Diseases Society of America 1, 3
• 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, as recommended by the World Health Organization 1, 3

Infection Control Measures

• Hand hygiene should be performed after using the toilet, changing diapers, before and after preparing food, and before eating, as recommended by the Centers for Disease Control and Prevention 1, 3
• Use of gloves, gowns, and proper hand hygiene is essential when caring for patients with diarrhea, according to the Centers for Disease Control and Prevention 1, 3
• Asymptomatic contacts of people with bacterial gastroenteritis do not need treatment but should follow appropriate infection prevention measures, as recommended by the Infectious Diseases Society of America 5, 6

Monitoring and Follow-up

• Continue monitoring hydration status until symptoms resolve, as recommended by the Infectious Diseases Society of America 1, 2
• Antimicrobial therapy should be modified or discontinued when a specific pathogen is identified from diagnostic tests, according to the Infectious Diseases Society of America 4, 6
• For persistent symptoms, reassessment of fluid and electrolyte balance, nutritional status, and antimicrobial therapy is recommended, as suggested by the Infectious Diseases Society of America 6

Cautions and Pitfalls

• Avoid antimotility agents in children under 18 years and in patients with bloody diarrhea or fever due to risk of complications, as recommended by the Centers for Disease Control and Prevention 1, 8
• Avoid antibiotics for STEC O157 infections as they may increase the risk of hemolytic uremic syndrome, according to the Infectious Diseases Society of America 5, 6
• Do not delay rehydration while waiting for diagnostic test results, as recommended by the Infectious Diseases Society of America 2

Medication Dosing in Acute Gastroenteritis

Oral Rehydration Solution Dosing

• The American College of Physicians recommends oral rehydration solution (ORS) as the primary treatment for acute gastroenteritis, with specific medication dosing reserved for symptom management and select clinical scenarios, according to the Infectious Diseases Society of America 9
• For mild to moderate dehydration, the Infectious Diseases Society of America recommends administering ORS 50-100 mL/kg over 3-4 hours in infants and children, or 2-4 L in adolescents and adults 9
• The Infectious Diseases Society of America suggests that children <10 kg should receive 60-120 mL ORS after each diarrheal stool or vomiting episode (maximum ~500 mL/day) 9
• The Infectious Diseases Society of America recommends that children >10 kg should receive 120-240 mL ORS after each diarrheal stool or vomiting episode (maximum ~1 L/day) 9
• The Infectious Diseases Society of America advises that adolescents and adults should receive ad libitum ORS, up to ~2 L/day 9
• In cases of severe dehydration, the Infectious Diseases Society of America recommends administering intravenous isotonic crystalloid (lactated Ringer's or normal saline) boluses of 20 mL/kg until pulse, perfusion, and mental status normalize 9

Loperamide (Antidiarrheal)

• The American Gastroenterological Association recommends an initial dose of 4 mg orally for loperamide in adults 10, 11, 12
• The American Gastroenterological Association suggests a maintenance dose of 2 mg after each unformed stool or every 4 hours for loperamide in adults 10, 11, 12
• The American Gastroenterological Association advises a maximum daily dose of 16 mg/day for loperamide in adults 10, 11, 12

Octreotide (For Complicated Diarrhea)

• The American Society of Clinical Oncology recommends an initial dose of 100-150 mcg subcutaneously three times daily for octreotide in complicated or severe diarrhea 10, 11, 12
• The American Society of Clinical Oncology suggests an alternative IV dosing of 25-50 mcg/hour continuous infusion for octreotide in complicated or severe diarrhea 10, 11, 12
• The American Society of Clinical Oncology advises a dose escalation of up to 500 mcg subcutaneously three times daily until diarrhea is controlled for octreotide in complicated or severe diarrhea 10, 11, 12, 13

Treatment for Gastroenteritis

Primary Treatment

• The American Gastroenterological Association recommends resuming an age-appropriate diet immediately after rehydration is completed, as there is no evidence that solid food delays recovery 14
• The American Gastroenterological Association suggests that small, light meals guided by appetite once rehydrated are appropriate 14
• The American Gastroenterological Association advises avoiding fatty, heavy, spicy foods, caffeine, and lactose-containing foods if diarrhea is prolonged 14

Symptomatic Management

• The International Society of Travel Medicine recommends that loperamide is appropriate for adults with mild, non-bloody diarrhea, but should never be used in children under 18 years 15
• The International Society of Travel Medicine suggests that adult dosing of loperamide should be an initial 4 mg orally, then 2 mg after each loose stool (maximum 16 mg/day) 15
• The International Society of Travel Medicine advises that loperamide may be combined with ORS for mild traveler's diarrhea in adults 15

Red Flags Requiring Medical Evaluation

• The American Academy of Pediatrics recommends that patients should seek immediate medical care if there is no improvement within 48 hours 14
• The American Academy of Pediatrics suggests that patients should seek immediate medical care if symptoms worsen or overall condition deteriorates 14
• The American Academy of Pediatrics advises that patients should seek immediate medical care if they experience severe vomiting preventing oral intake 14
• The American Academy of Pediatrics recommends that patients should seek immediate medical care if they have persistent fever 14
• The American Academy of Pediatrics suggests that patients should seek immediate medical care if they have frank blood in stools 14
• The American Academy of Pediatrics advises that patients should seek immediate medical care if they have abdominal distension 14