Management of Diverticulitis
Initial Classification and Diagnosis
For patients with suspected diverticulitis, obtain CT scan with IV contrast to confirm diagnosis and classify as uncomplicated (localized inflammation only) versus complicated (abscess, perforation, fistula, obstruction, or bleeding), as this classification drives all subsequent management decisions. 1, 2
- CT scan has 98-99% sensitivity and 99-100% specificity for diagnosing acute diverticulitis 3, 4
- Approximately 85-88% of cases are uncomplicated diverticulitis 1, 3
- Laboratory workup should include CBC, CRP, and basic metabolic panel to assess for high-risk features 2, 3
Management of Uncomplicated Diverticulitis
Step 1: Determine Need for Antibiotics
Most immunocompetent patients with uncomplicated diverticulitis do NOT require antibiotics, as multiple high-quality randomized trials demonstrate that antibiotics neither accelerate recovery nor prevent complications or recurrence. 1, 2
Reserve antibiotics ONLY for patients with these specific high-risk features: 1, 2
- Immunocompromised status (chemotherapy, high-dose steroids, organ transplant) 1, 2, 3
- Age >80 years 1, 2
- Pregnancy 1, 2
- Persistent fever or chills despite supportive care 1, 2
- Increasing leukocytosis 1, 2
- CRP >140 mg/L 1, 2
- WBC >15 × 10⁹ cells/L 1, 2
- Vomiting or inability to maintain oral hydration 1, 2
- Symptoms lasting >5 days 1, 2
- ASA score III or IV 1, 2
- CT findings of fluid collection, longer segment of inflammation, or pericolic extraluminal air 1, 2
- Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 1, 3
Step 2: Select Antibiotic Regimen (If Indicated)
Outpatient Oral Regimens (4-7 days for immunocompetent patients): 1, 2
- 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
Inpatient IV Regimens (transition to oral as soon as tolerated): 1, 2
Step 3: Determine Inpatient vs. Outpatient Management
Outpatient management is appropriate when ALL of the following criteria are met: 1, 2
- Able to tolerate oral fluids and medications 1, 2
- Temperature <100.4°F 1, 2
- Pain controlled with acetaminophen alone (pain score <4/10) 1, 2
- No significant comorbidities or frailty 1, 2
- Adequate home and social support 1, 2
- No signs of systemic inflammatory response or sepsis 1, 2
Hospitalization is required for: 1, 2
- Complicated diverticulitis 1, 2
- Inability to tolerate oral intake 1, 2
- Severe pain or systemic symptoms 1, 2
- Significant comorbidities or frailty 1, 2
- Immunocompromised status 1, 2
Step 4: Supportive Care
For all patients with uncomplicated diverticulitis: 1, 2
- Clear liquid diet during acute phase, advancing as symptoms improve 1, 2
- Pain control with acetaminophen (avoid NSAIDs and opioids) 1, 2
- Bowel rest initially 1, 2
Management of Complicated Diverticulitis
Small Abscesses (<4-5 cm)
Treat with IV antibiotics alone for 7 days with gram-negative and anaerobic coverage. 1, 2
Large Abscesses (≥4-5 cm)
Perform percutaneous CT-guided drainage PLUS IV antibiotics. 1, 2
- Continue antibiotics for 4 days after adequate source control in immunocompetent patients 1, 2
- Continue for up to 7 days in immunocompromised or critically ill patients 1, 2
Generalized Peritonitis or Sepsis
Obtain emergent surgical consultation for source control surgery (Hartmann's procedure or primary resection with anastomosis). 1, 2
- Initiate IV fluid resuscitation immediately 1, 2
- Start broad-spectrum IV antibiotics immediately 1, 2
Follow-Up and Monitoring
Mandatory Re-evaluation
Re-evaluate within 7 days from diagnosis, or sooner if clinical condition deteriorates. 1, 2
- If symptoms persist after 5-7 days of antibiotics, obtain repeat CT imaging to assess for complications 1, 2
- Do not simply extend antibiotics without imaging if treatment fails 1, 2
Colonoscopy Timing
Perform colonoscopy 6-8 weeks after symptom resolution for: 5, 1
- Complicated diverticulitis (7.9% risk of colon cancer) 5, 1
- First episode of uncomplicated diverticulitis 5, 1
- Patients >50 years requiring routine screening 5, 1
- Patients who have not had high-quality colonoscopy in the past year 5, 1
Prevention of Recurrence
Dietary and Lifestyle Modifications
Recommend the following evidence-based interventions to reduce recurrence risk: 5, 1, 2
- High-quality diet: High in fiber from fruits, vegetables, whole grains, and legumes (>22.1 g/day); low in red meat and sweets 5, 1, 2
- Regular vigorous physical activity 5, 1, 2
- Achieve or maintain BMI 18-25 kg/m² 5, 1, 2
- Smoking cessation 5, 1, 2
- Avoid regular use of NSAIDs and opioids when possible 5, 1, 2
What NOT to Restrict
Do NOT advise patients to avoid nuts, popcorn, seeds, or small-seeded fruits, as these are not associated with increased risk of diverticulitis and may reduce overall fiber intake. 5, 1, 2
Medications to AVOID for Prevention
Do NOT prescribe mesalamine for prevention of recurrent diverticulitis (strong recommendation, moderate quality evidence). 5, 1
Do NOT prescribe rifaximin or probiotics for prevention of recurrent diverticulitis. 5, 1
Surgical Considerations for Recurrent Diverticulitis
When to Consider Elective Sigmoidectomy
Elective sigmoidectomy should be considered (NOT based on number of episodes alone) when: 5, 1
- ≥3 episodes of CT-confirmed diverticulitis within 2 years 5, 1
- Persistent symptoms >3 months (smoldering diverticulitis) 5, 1
- Significant quality of life impairment 5, 1
- History of complicated diverticulitis 5, 1
- Immunocompromised status 5, 1
The DIRECT trial demonstrated significantly better quality of life at 6 months and 5-year follow-up after elective sigmoidectomy compared with continued conservative management in patients with recurrent/persistent symptoms. 5, 1
Important Context
- Only ~20% of patients experience recurrence within 5 years after initial episode 5
- Risk of complications requiring emergency surgery is low (<5%) 5
- Elective surgery reduces recurrence by absolute risk difference of 21.5% but carries 10% short-term complication rate and 25% long-term complications 5, 1
Critical Pitfalls to Avoid
Do not routinely prescribe antibiotics for uncomplicated diverticulitis in immunocompetent patients without risk factors. 1, 2
Do not assume all patients require hospitalization—most can be safely managed as outpatients with appropriate follow-up, resulting in 35-83% cost savings. 1, 2
Do not apply the "no antibiotics" approach to complicated diverticulitis (Hinchey 1b or higher), as the evidence specifically excluded these patients. 1, 2
Do not stop antibiotics early if they are indicated, even if symptoms improve. 1, 2
Do not delay surgical consultation in patients with frequent recurrences significantly affecting quality of life. 5, 1
Do not withhold antibiotics from patients with sepsis due to diverticulitis, regardless of other circumstances. 1, 2
Do not unnecessarily restrict nuts, seeds, and popcorn, as this is not evidence-based and may reduce overall fiber intake. 5, 1, 2