What is the recommended treatment for an acute diverticulitis flare?

Treatment of Acute Diverticulitis Flare

For immunocompetent patients with uncomplicated diverticulitis, antibiotics are not recommended as first-line therapy, and management should focus on supportive care with clear liquid diet and pain control. 1

Classification and Diagnosis

• Uncomplicated diverticulitis is defined as localized diverticular inflammation without abscess or perforation, typically confirmed by CT scan showing diverticula, wall thickening, and increased density of pericolic fat 1
• Complicated diverticulitis involves abscess formation, perforation, fistula, or obstruction 1, 2

Treatment Algorithm for Uncomplicated Diverticulitis

First-Line Management (Uncomplicated Cases)

• Clear liquid diet during the acute phase, advancing as symptoms improve 1
• Pain management with acetaminophen as the preferred analgesic 2
• Observation without antibiotics for immunocompetent patients with mild uncomplicated diverticulitis 1
• Re-evaluation within 7 days; earlier if clinical condition deteriorates 1

When to Use Antibiotics in Uncomplicated Diverticulitis

Antibiotics should be reserved for patients with:

• Systemic manifestations of infection 1
• Immunocompromised status 1, 2
• Advanced age (>80 years) 1, 2
• Significant comorbidities 1
• CRP >140 mg/L or WBC >15 × 10^9/L 1
• Pregnancy 2
• Longer segment of inflammation or fluid collection on CT 1

Antibiotic Selection When Indicated

• Oral antibiotics are preferred whenever possible 1
• First-line oral options: amoxicillin-clavulanate or ciprofloxacin plus metronidazole 2, 3
• For patients unable to tolerate oral intake: IV antibiotics (ceftriaxone plus metronidazole, ampicillin-sulbactam, or piperacillin-tazobactam) 2
• Duration: 4-7 days for immunocompetent patients; up to 7 days for immunocompromised or critically ill patients 1

Treatment of Complicated Diverticulitis

Small Abscesses (<4-5 cm)

• Antibiotic therapy alone for 7 days 1

Large Abscesses (>4-5 cm)

• Percutaneous drainage combined with antibiotic therapy for 4 days 1
• If percutaneous drainage is not feasible, consider antibiotic therapy alone with close monitoring 1
• Surgical intervention if clinical deterioration occurs 1

Outpatient vs. Inpatient Management

Outpatient Management Criteria

• Uncomplicated diverticulitis 1
• No significant comorbidities 1
• Ability to take fluids orally 1
• Ability to self-manage at home 1
• Adequate pain control 1

Inpatient Management Criteria

• Complicated diverticulitis 1, 2
• Significant comorbidities 1
• Inability to tolerate oral intake 1
• Severe pain or systemic symptoms 1
• Failure of outpatient management 4

Important Considerations and Pitfalls

• Failure to recognize high-risk patients who need antibiotics despite having uncomplicated disease can lead to progression to complicated diverticulitis 1
• Unnecessary use of antibiotics in low-risk patients with uncomplicated diverticulitis provides no benefit and contributes to antibiotic resistance 1
• Young patients (<50 years) and those with high pain scores (≥8/10) have increased risk for complicated or recurrent diverticulitis and should be monitored more closely 1
• The transition from IV to oral antibiotics should be made as soon as possible to facilitate earlier discharge 1
• Follow-up colonoscopy is not routinely recommended for CT-proven uncomplicated diverticulitis but should be considered for patients with diverticular abscesses to rule out underlying malignancy 1