Treatment of Diverticulitis
Most immunocompetent patients with uncomplicated diverticulitis do NOT require antibiotics and should be managed with observation, clear liquid diet, and acetaminophen for pain control. 1
Initial Diagnostic Confirmation
Obtain CT scan with IV contrast to confirm diagnosis and classify disease severity—this is the gold standard with 98-99% sensitivity and 99-100% specificity. 1, 2
- Uncomplicated diverticulitis: Localized inflammation without abscess, perforation, fistula, obstruction, or bleeding 1, 2
- Complicated diverticulitis: Presence of abscess, perforation, fistula, obstruction, or bleeding 1, 2
- Approximately 85-88% of cases are uncomplicated 1, 2
Treatment Algorithm for Uncomplicated Diverticulitis
Step 1: Determine if Antibiotics Are Needed
Reserve antibiotics ONLY for patients with specific high-risk features: 1
- Immunocompromised status (chemotherapy, high-dose steroids, organ transplant) 1, 2
- Age >80 years 1, 2
- Pregnancy 1, 2
- Persistent fever or chills despite supportive care 1
- Increasing leukocytosis 1
- CRP >140 mg/L 1
- WBC >15 × 10⁹ cells/L 1
- Refractory symptoms or vomiting 1
- Inability to maintain oral hydration 1
- Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 1, 2
- CT findings: fluid collection, longer segment of inflammation, or pericolic extraluminal air 1
- ASA score III or IV 1
- Symptoms >5 days prior to presentation 1
Step 2: Outpatient vs. Inpatient Management
Outpatient management is appropriate when patients meet ALL criteria: 1
- Can tolerate oral fluids and medications 1
- Temperature <100.4°F 1
- Pain controlled with acetaminophen alone (pain score <4/10) 1
- No significant comorbidities or frailty 1
- Adequate home and social support 1
- No signs of sepsis or peritonitis 1
Hospitalize patients with: 1
- Complicated diverticulitis 1
- Inability to tolerate oral intake 1
- Systemic inflammatory response or sepsis 1
- Significant comorbidities or frailty 1
- Immunocompromised status 1
Step 3: Antibiotic Regimens (When Indicated)
Outpatient Oral Therapy (4-7 days for immunocompetent patients): 1
- First-line: Ciprofloxacin 500 mg orally twice daily PLUS metronidazole 500 mg orally three times daily 1, 2
- Alternative: Amoxicillin-clavulanate 875/125 mg orally twice daily 1, 2
- Ceftriaxone PLUS metronidazole 1, 2
- Piperacillin-tazobactam 1, 2
- Transition to oral antibiotics as soon as patient tolerates oral intake to facilitate earlier discharge 1
Duration of Therapy: 1
Step 4: Supportive Care for All Patients
- Clear liquid diet during acute phase, advancing as symptoms improve 1
- Acetaminophen for pain control (avoid NSAIDs and opioids) 1
- Adequate hydration 1
Treatment of Complicated Diverticulitis
Small Abscesses (<4-5 cm)
- IV antibiotics alone for 7 days with gram-negative and anaerobic coverage 1
- Monitor closely for clinical improvement 1
Large Abscesses (≥4-5 cm)
- Percutaneous CT-guided drainage PLUS IV antibiotics 1
- Continue antibiotics for 4 days after adequate source control in immunocompetent patients 1
- Up to 7 days for immunocompromised or critically ill patients 1
Generalized Peritonitis or Sepsis
- Emergent surgical consultation 1
- IV antibiotics immediately 1
- Surgical options: Hartmann's procedure or primary resection with anastomosis 1
Mandatory Follow-Up and Monitoring
Re-evaluate within 7 days from diagnosis, or sooner if clinical condition deteriorates. 1
Colonoscopy 6-8 weeks after symptom resolution for: 1
- Complicated diverticulitis 1
- First episode of uncomplicated diverticulitis 1
- Patients >50 years requiring routine screening 1
- Risk of colorectal cancer is 1.16% in uncomplicated cases, 7.9% in complicated cases 1
Prevention of Recurrence
High-quality diet: 1
- >22.1 g/day of fiber from fruits, vegetables, whole grains, and legumes 1
- Low in red meat and sweets 1
- Fiber from fruits appears most protective 1
Lifestyle modifications: 1
- Regular vigorous physical activity 1
- Achieve or maintain normal BMI (18-25 kg/m²) 1
- Smoking cessation 1
- Avoid regular use of NSAIDs and opioids when possible 1
Do NOT prescribe for prevention: 1
- Mesalamine (strong recommendation against) 1
- Rifaximin (conditional recommendation against) 1
- Probiotics (conditional recommendation against) 1
Surgical Considerations for Recurrent Diverticulitis
Elective sigmoidectomy should be individualized based on: 1
- Quality of life impact 1
- Frequency of recurrence (≥3 episodes within 2 years) 1
- Duration of persistent symptoms (>3 months) 1
- Patient preferences 1
The traditional "two-episode rule" is no longer accepted. 1
Evidence from DIRECT trial: Elective sigmoidectomy resulted in significantly better quality of life at 6 months and 5-year follow-up compared with continued conservative management in patients with recurrent/persistent symptoms. 1
Critical Pitfalls to Avoid
- Do NOT routinely prescribe antibiotics for uncomplicated diverticulitis in immunocompetent patients without risk factors 1
- Do NOT assume all patients require hospitalization—outpatient management results in 35-83% cost savings per episode 1
- Do NOT unnecessarily restrict nuts, seeds, and popcorn—this is not evidence-based and may reduce overall fiber intake 1
- Do NOT stop antibiotics early if they are indicated, even if symptoms improve 1
- Do NOT apply the "no antibiotics" approach to Hinchey 1b/2 or higher disease—the evidence specifically excluded these patients 1
- Do NOT delay surgical consultation in patients with frequent recurrence affecting quality of life 1
Special Population Considerations
Immunocompromised patients: 1
- Lower threshold for CT imaging, antibiotic treatment, and surgical consultation 1
- Longer antibiotic duration (10-14 days) required 1
- Higher risk for perforation and death, especially with corticosteroid use 1
Elderly patients (>65 years): 1