What is the management of acute diverticulitis?

Management of Acute Diverticulitis

Antibiotics should be used selectively, rather than routinely, in patients with acute uncomplicated diverticulitis, while complicated diverticulitis requires more aggressive intervention including antibiotics, percutaneous drainage for abscesses ≥4-5 cm, and possible surgical management for peritonitis or other complications. 1, 2

Diagnosis and Assessment

• Preferred diagnostic test: CT scan with IV contrast (sensitivity 98%, specificity 99%) 2
• Key findings on imaging: Intestinal wall thickening, signs of inflammation in pericolonic fat, thickening of lateroconal fascia, and pericolonic or distant abscess 2
• Laboratory markers: Increased white blood cell count, leukocyte shift to left (>75%), elevated C-reactive protein, and procalcitonin 2

Management Algorithm

Uncomplicated Diverticulitis (85% of cases)

1. First-line therapy: Observation with pain management (typically acetaminophen) and dietary modification with a clear liquid diet 3

2. Antibiotics: Reserved for specific patient populations:

   • Patients with systemic symptoms (persistent fever or chills)
   • Increasing leukocytosis
   • Age >80 years
   • Pregnant patients
   • Immunocompromised patients
   • Patients with chronic medical conditions (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 3

3. Antibiotic options when indicated:

   • Oral: Amoxicillin/clavulanic acid or cefalexin with metronidazole 3
   • IV (if unable to tolerate oral intake): Cefuroxime or ceftriaxone plus metronidazole or ampicillin/sulbactam 3
   • Duration: Limited to 4-7 days 2

Complicated Diverticulitis

1. Small abscesses (<4-5 cm):

   • Antibiotics alone for 7 days 2

2. Large abscesses (≥4-5 cm):

   • Percutaneous drainage combined with antibiotics for 4 days 2
   • IV antibiotic options: Piperacillin/tazobactam, ertapenem, ceftriaxone plus metronidazole 2, 3
   • For beta-lactam allergies: Eravacycline or tigecycline 2

3. Peritonitis or other severe complications:

   • Emergent laparotomy with colonic resection 3
   • IV antibiotics (as above)

Follow-up Care

• Colonoscopy: Recommended 4-6 weeks after resolution of complicated diverticulitis to rule out malignancy 2
• Monitoring: Patients should be monitored for treatment failure, with persistent symptoms or worsening clinical condition warranting further diagnostic investigation 2

Prevention Strategies

• Diet: High-fiber diet or fiber supplementation is recommended 1, 2
• Physical activity: Regular vigorous physical activity is advised 1, 2
• Medications to avoid/limit:
  • Non-aspirin NSAIDs should be avoided if possible 1
  • No need to avoid seeds, nuts, and popcorn 1
  • No need to avoid aspirin 1

Important Considerations and Pitfalls

• Outpatient treatment: Many patients with uncomplicated diverticulitis can be managed as outpatients with oral antibiotics (when indicated), clear liquid diet, and pain control 4
• Surgical decisions: Elective colonic resection is not routinely recommended after an initial episode of acute uncomplicated diverticulitis 1
• Ineffective treatments: Mesalamine, rifaximin, and probiotics are not recommended after acute uncomplicated diverticulitis 1
• Mortality risk: Postoperative mortality is 0.5% for elective colon resection but rises to 10.6% for emergent colon resection 3
• Treatment failure: Initial trial of antibiotics alone has a failure rate of approximately 20% in complicated cases 2

The management approach should be guided by the severity of the disease, with uncomplicated cases often requiring minimal intervention while complicated cases need more aggressive treatment to prevent morbidity and mortality.