What is the management of diverticulitis?

Management of Diverticulitis

Initial Classification and Risk Stratification

For immunocompetent patients with uncomplicated diverticulitis without systemic inflammatory signs, antibiotics are NOT recommended as first-line therapy—observation with supportive care is the preferred approach. 1

Define the Type of Diverticulitis

• Uncomplicated diverticulitis shows localized inflammation with wall thickening and pericolic fat stranding on CT, without abscess or perforation 2
• Complicated diverticulitis demonstrates pericolic air bubbles, abscess formation, distant free air, or diffuse peritonitis on imaging 2
• CT with IV contrast is the gold standard diagnostic test with 98-99% sensitivity and 99-100% specificity 3

Management Algorithm for Uncomplicated Diverticulitis

Step 1: Determine Need for Antibiotics

Most immunocompetent patients do NOT require antibiotics, as multiple high-quality trials (including the DIABOLO trial with 528 patients) demonstrate antibiotics neither accelerate recovery nor prevent complications or recurrence 1

Reserve antibiotics ONLY for patients with:

• Immunocompromised status (chemotherapy, organ transplant, high-dose steroids) 1, 3
• Systemic inflammatory response or sepsis 1, 2
• Age >80 years 1
• Pregnancy 1
• White blood cell count >15 × 10⁹ cells/L 1
• C-reactive protein >140 mg/L 1
• Symptoms lasting >5 days 1
• Presence of vomiting or inability to maintain hydration 1
• Fluid collection or longer segment of inflammation on CT 1
• ASA score III or IV 1
• Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 3

Step 2: Choose Treatment Setting

Outpatient management is appropriate when:

• Patient is afebrile and clinically stable 2
• Can tolerate oral fluids and medications 1
• No significant comorbidities or frailty 1
• Adequate home support available 1
• Pain score <4/10 controlled with acetaminophen 1

Hospitalization is required for:

• Complicated diverticulitis 2
• Inability to tolerate oral intake 1
• Systemic inflammatory response or sepsis 2
• Significant comorbidities or frailty 1
• Immunocompromised status 1

Step 3: Supportive Care (All Patients)

• Clear liquid diet during acute phase, advancing as symptoms improve 1
• Bowel rest and adequate hydration 2
• Pain control with acetaminophen (avoid NSAIDs) 1, 3

Step 4: Antibiotic Regimens (When Indicated)

Outpatient oral regimens (4-7 days for immunocompetent patients):

• First-line: Amoxicillin-clavulanate 875/125 mg orally twice daily 1, 3
• Alternative: Ciprofloxacin 500 mg orally twice daily PLUS metronidazole 500 mg orally three times daily 1, 3

Inpatient IV regimens (transition to oral as soon as tolerated):

• Ceftriaxone PLUS metronidazole 1, 3
• Piperacillin-tazobactam 1, 3
• Ampicillin-sulbactam 3

Duration:

• 4-7 days for immunocompetent patients 1
• 10-14 days for immunocompromised patients 1

Management of Complicated Diverticulitis

Abscess Management

• Small abscesses (<4-5 cm): Antibiotics alone may be sufficient 1, 2
• Large abscesses (≥4-5 cm): Percutaneous drainage PLUS IV antibiotics 1, 2
• Duration after drainage: 4 days for immunocompetent patients with adequate source control; up to 7 days for immunocompromised or critically ill patients 1

Surgical Indications

Urgent surgical consultation required for:

• Generalized peritonitis 1, 3
• Failed medical management 1
• Hemodynamic instability 4
• Inability to drain abscess percutaneously 1

Surgical options:

• Primary resection with anastomosis (preferred in stable patients) 1
• Hartmann procedure (reserved for critically ill patients with diffuse peritonitis) 1

Follow-Up and Monitoring

• Re-evaluation within 7 days is mandatory; earlier if clinical deterioration occurs 1, 2
• Colonoscopy 4-6 weeks after resolution for patients with complicated diverticulitis or those who haven't had high-quality colonoscopy in the past year 1, 4
• Monitor for predictors of progression: symptoms >5 days, pain score >7, vomiting, high leukocyte count, elevated CRP 2

Prevention of Recurrence

Dietary and lifestyle modifications:

• High-quality diet: High in fiber from fruits, vegetables, whole grains, legumes; low in red meat and sweets 1
• Fiber intake >22.1 g/day shows statistically significant protective effect 1
• Regular vigorous physical activity 5, 1
• Achieve or maintain normal BMI 1
• Smoking cessation 1
• Avoid non-aspirin NSAIDs when possible 5, 1

What NOT to restrict:

• Do NOT avoid nuts, corn, popcorn, or small-seeded fruits—these are NOT associated with increased diverticulitis risk 5, 1

Medications to avoid:

• Do NOT use mesalamine for prevention (strong recommendation against) 5
• Do NOT use rifaximin for prevention 5
• Do NOT use probiotics for prevention 5

Elective Surgery Considerations

• The traditional "two-episode rule" is no longer accepted 1
• Decision should be based on quality of life impact, frequency of recurrence, and risk of complicated disease—NOT number of episodes 1
• The DIRECT trial demonstrated significantly better quality of life at 6 months with elective sigmoidectomy versus 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, 2
• Do NOT apply the "no antibiotics" approach to Hinchey 1b/2 or higher disease—these patients require antibiotics 1
• Do NOT assume all patients require hospitalization—most can be managed outpatient with 35-83% cost savings 1
• Do NOT unnecessarily restrict diet (nuts, seeds, popcorn)—this is not evidence-based 5, 1
• Do NOT delay surgical consultation in patients with frequent recurrences affecting quality of life 1
• Do NOT stop antibiotics early if indicated, even if symptoms improve 1
• Do NOT fail to recognize high-risk features for progression to complicated disease 2