What is the appropriate treatment approach for a patient with suspected enteritis?

Treatment of Suspected Enteritis

For suspected enteritis, initiate immediate broad-spectrum antibiotics with bowel rest only in specific high-risk scenarios: infants <3 months, immunocompromised patients with severe illness and bloody diarrhea, suspected Shigella with bacillary dysentery syndrome, recent international travelers with fever ≥38.5°C or sepsis signs, or suspected enteric fever; otherwise, prioritize aggressive rehydration and withhold empiric antibiotics while awaiting diagnostic results. 1, 2

Critical Decision Point: Who Needs Immediate Antibiotics?

The treatment approach fundamentally depends on patient risk stratification and clinical presentation, not simply the presence of enteritis symptoms.

START Empiric Antibiotics Immediately For:

• Infants <3 months of age with suspected bacterial etiology: Use third-generation cephalosporin 1, 2
• Bacillary dysentery syndrome (frequent scant bloody stools, tenesmus, fever, abdominal pain): Presumed Shigella requiring immediate treatment 1, 2
• Recent international travelers with body temperature ≥38.5°C (101.3°F) and/or signs of sepsis 1, 2
• Immunocompromised patients with severe illness and bloody diarrhea 1, 2
• Suspected enteric fever with sepsis features: Requires broad-spectrum therapy after obtaining blood, stool, and urine cultures 1, 3

WITHHOLD Empiric Antibiotics For:

• Immunocompetent children and adults with bloody diarrhea while awaiting test results (strong recommendation, low-quality evidence) 2
• Suspected STEC O157 or Shiga toxin-producing E. coli: Antibiotics increase risk of hemolytic uremic syndrome 1, 2
• Mild self-limited gastroenteritis: Modest benefit (approximately 1 day symptom reduction) is outweighed by risks including prolonged Salmonella shedding and emergence of quinolone-resistant Campylobacter 2

Specific Antibiotic Regimens When Indicated

For Adults:

• First-line: Azithromycin OR fluoroquinolone (ciprofloxacin) based on local susceptibility patterns and travel history 1, 2
• Enteric fever (hospitalized/severe): Ceftriaxone 2g IV daily for 5-7 days, continued for 14 days total to reduce relapse risk 3
• Enteric fever (uncomplicated): Azithromycin 1g daily for 7 days 3
• Avoid fluoroquinolones for cases originating from South Asia due to >70% resistance rates 3

For Children:

• Infants <3 months or neurologic involvement: Third-generation cephalosporin 1, 2
• Otherwise: Azithromycin based on local susceptibility and travel history 1, 2

For Complicated Intra-abdominal Infections:

• Community-acquired, mild-to-moderate: Ciprofloxacin plus metronidazole 4, 5
• High-risk or severe: Carbapenem (imipenem-cilastatin, meropenem, doripenem) OR piperacillin-tazobactam 4

Special Populations Requiring Modified Approach

Neutropenic Enteritis/Typhlitis:

• Treatment is non-operative with antibiotics and bowel rest 4
• Immediate broad-spectrum antibiotics per IDSA "fever with neutropenia" guidelines: Anti-pseudomonal β-lactam agent OR carbapenem OR piperacillin-tazobactam as monotherapy 4
• Surgery reserved only for perforation or ischemia signs 4
• Mortality reaches 29.5% with positive radiologic signs; bowel wall thickening >10 mm carries 60% death risk vs. 4.2% if <10 mm 4
• Resolution occurs in 86% with conservative antibiotic treatment in median 6-8 days 4

Cytomegalovirus Colitis:

• Treatment is non-operative: Antiviral therapy, broad-spectrum antibiotics, and bowel rest 4
• Emergency surgery only for toxic megacolon, fulminant colitis, perforation, or ischemia 4

Essential Supportive Care (All Patients)

Fluid Resuscitation:

• Rapid restoration of intravascular volume for all patients with suspected intra-abdominal infection 4
• Immediate resuscitation when hypotension identified in septic shock 4
• Reduced osmolarity oral rehydration solution (ORS) for mild-to-moderate dehydration 1
• IV fluids for severe dehydration, shock, or altered mental status 1

Antimicrobial Timing:

• Septic shock: Administer antibiotics as soon as possible, ideally within 1 hour 4, 1
• Without septic shock: Start in emergency department within 8 hours of presentation 4
• Maintain satisfactory drug levels during any source control intervention 4

Diagnostic Workup Before Treatment

Obtain Cultures BEFORE Starting Antibiotics:

• Blood cultures have highest yield within first week for enteric fever 3
• Stool samples for C. difficile toxin testing in hospitalized patients with diarrhea and recent antibiotic exposure 1
• Multiplex antimicrobial testing is preferred over traditional stool cultures 6

Imaging When Indicated:

• CT scan is imaging modality of choice for suspected intra-abdominal infection in adults not undergoing immediate laparotomy 4
• CT detection of right colon wall thickening is best indicator and prognostic predictor for neutropenic enteritis 4

Duration of Therapy

• Complicated intra-abdominal infections: Limit to 4-7 days unless difficult to achieve adequate source control 4
• Enteric fever: Continue for 14 days to reduce relapse risk (<8% for ceftriaxone, <3% for azithromycin) 3
• Bowel trauma repaired within 12 hours: Prophylactic antibiotics for 24 hours only 4
• Acute appendicitis without perforation: Discontinue within 24 hours 4

Critical Pitfalls to Avoid

• Never assume fever + bloody diarrhea = automatic antibiotics: Presence of fever alone does NOT mandate treatment unless meeting specific high-risk criteria 2
• Always consider STEC even with fever: Antibiotics can precipitate hemolytic uremic syndrome 1, 2
• Do not add vancomycin empirically for persistent fever without evidence of gram-positive infection 1
• Do not treat asymptomatic contacts of patients with bloody diarrhea 1
• Modify or discontinue antibiotics when specific pathogen identified 1, 2
• Obtain new blood cultures if fever persists >3 days despite empiric therapy 1
• Test for C. difficile in any patient with recent antibiotic exposure or healthcare contact 1