What is the treatment for diverticulitis?

Treatment of Diverticulitis

For acute uncomplicated diverticulitis, outpatient management without antibiotics is recommended as first-line therapy, with antibiotics reserved only for patients with systemic symptoms or specific risk factors. 1

Classification and Diagnosis

Diverticulitis is classified into two main categories:

• Uncomplicated diverticulitis: Localized inflammation without abscess, phlegmon, fistula, obstruction, bleeding, or perforation 1
• Complicated diverticulitis: Inflammation with abscess, phlegmon, fistula, obstruction, bleeding, or perforation 1

Diagnosis should include:

• CT scan with IV contrast (98% sensitivity, 99% specificity) as the first-line imaging modality 1
• Clinical assessment alone is insufficient, especially in elderly patients 1

Treatment Algorithm

1. Uncomplicated Diverticulitis (85% of cases)

First-line approach:

• Observation with pain management (typically acetaminophen) 2
• Clear liquid diet transitioning to fiber-rich diet 1
• No antibiotics for most patients 1

Antibiotics indicated only for patients with:

• Systemic symptoms (persistent fever or chills)
• Increasing leukocytosis
• Age >80 years
• Pregnancy
• Immunocompromised status (chemotherapy, high-dose steroids, organ transplant)
• Chronic medical conditions (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 1, 2

Antibiotic options when indicated:

• Oral: Amoxicillin/clavulanic acid or cefalexin with metronidazole 2
• IV (for those unable to tolerate oral intake): Cefuroxime or ceftriaxone plus metronidazole, or ampicillin/sulbactam 2

2. Complicated Diverticulitis

Treatment approach:

• Broad-spectrum IV antibiotics covering gram-negative bacilli and anaerobes:

  • Piperacillin-tazobactam, ertapenem, meropenem, or imipenem/cilastatin
  • Combination therapy: Ceftriaxone + metronidazole, ciprofloxacin + metronidazole, or ampicillin + gentamicin + metronidazole 1

• For abscesses:

  • <4 cm: Antibiotics alone may be sufficient

  • 4 cm: Percutaneous drainage plus antibiotics 1

  • Culture drainage fluid to guide antibiotic therapy 1

• Surgical intervention for:

  • Distant intraperitoneal free air
  • Diffuse peritonitis
  • Other severe complications 1

Surgical options:

• Hemodynamically stable: Resection and anastomosis with/without stoma
• Unstable or multiple comorbidities: Hartmann's procedure 1

Follow-up and Prevention

• Colonoscopy 6-8 weeks after resolution to exclude colonic neoplasm (if not recently performed) 1
• Fiber-rich diet including fruits, vegetables, whole grains, and legumes 1
• Regular physical activity 1
• Smoking cessation 1
• Avoidance of NSAIDs, opiates, and corticosteroids 1

Important Considerations

• Outpatient treatment is viable in approximately 95% of uncomplicated cases, with similar safety and efficacy to inpatient treatment 3
• Warning signs for progression to complicated disease: symptoms >5 days before presentation, vomiting, high C-reactive protein levels, pericolic extraluminal air, or fluid collection on CT 1
• Surgical mortality varies significantly: 0.5% for elective resection vs. 10.6% for emergent resection 2
• Timing matters: Delay between diagnosis and surgery >60 hours increases mortality and need for relaparotomy 1

Common Pitfalls to Avoid

1. Overuse of antibiotics in uncomplicated cases - recent evidence shows they may not be necessary for mild to moderate uncomplicated diverticulitis 4
2. Relying solely on clinical assessment without imaging confirmation
3. Delaying surgical intervention when indicated (>60 hours increases mortality)
4. Neglecting follow-up colonoscopy to exclude malignancy
5. Failing to address modifiable risk factors for recurrence (low-fiber diet, physical inactivity, smoking, NSAID use)