What is the recommended treatment for diverticulitis?

Treatment of Diverticulitis

The treatment of diverticulitis should be stratified based on disease severity, with antibiotics used selectively rather than routinely in immunocompetent patients with uncomplicated diverticulitis, while antibiotics are mandatory for complicated diverticulitis or in immunocompromised patients. 1

Classification of Diverticulitis

• Uncomplicated diverticulitis: Localized diverticular inflammation without abscess or perforation, typically confirmed by CT scan showing diverticula, wall thickening, and increased density of pericolic fat 2
• Complicated diverticulitis: Involves abscess formation, perforation, fistula, or obstruction 2

Treatment of Uncomplicated Diverticulitis

First-Line Management

• Clear liquid diet during the acute phase, advancing as symptoms improve 2
• Pain management (typically acetaminophen) 3
• Observation without antibiotics for immunocompetent patients with mild uncomplicated diverticulitis 1
• Re-evaluation within 7 days; earlier if clinical deterioration occurs 2

When to Use Antibiotics in Uncomplicated Diverticulitis

Antibiotics should be reserved for patients with:

• Systemic manifestations of infection (persistent fever, chills) 1, 2
• Immunocompromised status 1
• Advanced age (>80 years) 2, 3
• Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 2, 3
• Laboratory abnormalities: CRP >140 mg/L or WBC >15 × 10^9/L 1, 2
• Longer segment of inflammation or fluid collection on CT 1, 2

Antibiotic Selection When Indicated

• Oral regimens (preferred whenever possible) 1, 4:

  • Amoxicillin-clavulanate 1, 3
  • Fluoroquinolone plus metronidazole 1, 5
  • Duration: 4-7 days for immunocompetent patients 1

• Intravenous regimens (for those unable to tolerate oral intake) 3, 4:

  • Ceftriaxone plus metronidazole 3
  • Ampicillin-sulbactam 3
  • Piperacillin-tazobactam (for more severe cases) 3
  • Switch to oral antibiotics as soon as possible 2, 4

Treatment of Complicated Diverticulitis

• Small abscesses (<4-5 cm): Antibiotic therapy alone for 7 days 2
• Large abscesses (>4-5 cm): Percutaneous drainage combined with antibiotic therapy 2
• Perforation with generalized peritonitis: Emergent laparotomy with colonic resection 3
• Duration of antibiotics: 7-10 days for immunocompetent patients; 10-14 days for immunocompromised patients 1

Outpatient vs. Inpatient Management

Outpatient Management Criteria

• Uncomplicated diverticulitis 2, 5
• Ability to tolerate oral intake 5
• Adequate pain control with oral medications 5
• Absence of significant comorbidities 5
• Reliable patient with good follow-up 5

Inpatient Management Criteria

• Complicated diverticulitis 2
• Significant comorbidities 2
• Inability to tolerate oral intake 2, 5
• Severe pain or systemic symptoms 2
• Immunocompromised status 1

Special Populations

Immunocompromised Patients

• Higher risk for complicated disease and treatment failure 1
• Lower threshold for CT imaging to assess for complications 1
• Mandatory antibiotic treatment even for uncomplicated diverticulitis 1
• Longer duration of antibiotic therapy (10-14 days) 1
• Consider surgical consultation 1

Important Considerations and Pitfalls

• Failure to recognize high-risk patients who need antibiotics despite having uncomplicated disease can lead to progression to complicated diverticulitis 2
• Unnecessary use of antibiotics in low-risk patients with uncomplicated diverticulitis provides no benefit and contributes to antibiotic resistance 1, 2
• Oral antibiotics are as effective as intravenous antibiotics for patients who can tolerate oral intake 4, 6
• Outpatient management of appropriate candidates is safe and cost-effective 5
• Follow-up colonoscopy is not routinely recommended for CT-proven uncomplicated diverticulitis but should be considered for patients with complicated diverticulitis to rule out underlying malignancy 2