What is the treatment for diverticulitis?

Treatment of Diverticulitis

For immunocompetent patients with uncomplicated diverticulitis without systemic inflammation, antibiotics are not recommended as first-line therapy. 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, 2
• Complicated diverticulitis involves abscess formation, perforation, fistula, obstruction, bleeding, or perforation 1, 2
• CT scan is the gold standard for diagnosis with 98-99% sensitivity and 99-100% specificity 3

Treatment Algorithm for Uncomplicated Diverticulitis

First-Line Management

• Observation with supportive care (clear liquid diet and pain control) without antibiotics for immunocompetent patients 4, 1, 2
• Multiple high-quality randomized controlled trials have demonstrated that antibiotic therapy neither accelerates recovery nor prevents complications or recurrence in uncomplicated diverticulitis 4, 5
• Pain management typically with acetaminophen 3
• Gradually advance diet as symptoms improve 1, 2
• Re-evaluation within 7 days; earlier if clinical condition deteriorates 1, 2

When to Use Antibiotics in Uncomplicated Diverticulitis

Antibiotics should be reserved for patients with:

• Immunocompromised status (receiving chemotherapy, high-dose steroids, or post-transplant) 1, 5, 3
• Systemic manifestations of infection or sepsis 1, 2, 3
• Advanced age (>80 years) 1, 3
• Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 1, 2, 3
• Laboratory abnormalities: CRP >140 mg/L or WBC >15 × 10^9/L 1, 2
• Imaging findings: longer segment of inflammation or fluid collection on CT 1, 2
• Pregnancy 1, 3

Antibiotic Selection When Indicated

• Oral regimens: amoxicillin-clavulanate or ciprofloxacin plus metronidazole for 4-7 days 1, 3, 6
• IV regimens (for patients unable to tolerate oral intake): ceftriaxone plus metronidazole, ampicillin/sulbactam, or piperacillin-tazobactam 1, 3
• Duration: 4-7 days for immunocompetent patients; 10-14 days for immunocompromised patients 1, 2

Treatment of Complicated Diverticulitis

• For small abscesses (<4-5 cm), antibiotic therapy alone is considered safe and effective 4, 2
• For large abscesses (>4-5 cm), percutaneous drainage combined with antibiotic therapy is recommended 4, 2
• Surgical intervention is required if the patient shows worsening of inflammatory signs or the abscess does not reduce with medical therapy 4

Outpatient vs. Inpatient Management

Outpatient Management Criteria

• Uncomplicated diverticulitis 1, 2, 7
• Ability to tolerate oral intake 1, 6
• Adequate pain control 1, 6
• Appropriate home support 1, 6
• Outpatient treatment is associated with cost savings of 35-83% per episode compared to inpatient management 1

Inpatient Management Criteria

• Complicated diverticulitis 1, 2
• Inability to tolerate oral intake 1, 2, 6
• Severe pain or systemic symptoms 1, 2
• Significant comorbidities or frailty 1, 2
• Immunocompromised status 1, 2

Prevention of Recurrence

• High-quality diet high in fiber from fruits, vegetables, whole grains, and legumes and low in red meat and sweets 1
• Regular physical activity, particularly vigorous exercise 1
• Achieving or maintaining normal body mass index 1
• Avoiding smoking 1
• Avoiding regular use of NSAIDs and opiates when possible 1

Common Pitfalls to Avoid

• Overuse of antibiotics in uncomplicated cases without risk factors contributes to antibiotic resistance without providing clinical benefit 1, 5, 2
• Failing to recognize high-risk patients who would benefit from antibiotics despite having uncomplicated disease 1, 5
• Restricting consumption of nuts, corn, popcorn, or small-seeded fruits unnecessarily, as these are not associated with increased risk of diverticulitis 1
• Inadequate follow-up to ensure resolution of symptoms can lead to delayed diagnosis of complications 5
• Missing signs of progression to complicated diverticulitis can lead to delayed treatment 5

Follow-up Recommendations

• Colonoscopy is not routinely recommended for CT-proven uncomplicated diverticulitis 1, 2
• Consider colonoscopy for patients with diverticular abscesses to rule out underlying malignancy 1
• For chronic symptoms that persist after diverticulitis, evaluation with both imaging and lower endoscopy is recommended 1