What is the treatment for diverticulitis?

Treatment of Diverticulitis

For patients with diverticulitis, uncomplicated cases should be managed with observation and pain control (typically acetaminophen), while antibiotics should be reserved for complicated cases or patients with specific risk factors. 1

Diagnosis

• Diverticulitis typically presents with:
  • Left lower quadrant abdominal pain
  • Fever
  • Change in bowel habits
  • Nausea
  • Elevated inflammatory markers 2
• Clinical suspicion alone is correct in only 40-65% of cases 2
• CT scan with oral and IV contrast is the gold standard for diagnosis (98-99% sensitivity/specificity) 2

Treatment Algorithm

Uncomplicated Diverticulitis (85% of cases)

1. First-line approach:

   • Observation with pain management (acetaminophen)
   • Dietary modification with clear liquid diet 1

2. Antibiotics indicated only for patients with:

   • Systemic symptoms (persistent fever/chills)
   • Increasing leukocytosis
   • Age >80 years
   • Pregnancy
   • Immunocompromised status
   • Chronic medical conditions (cirrhosis, CKD, heart failure, poorly controlled diabetes) 1

3. Antibiotic regimens for outpatient treatment:

   • First choice: Oral amoxicillin-clavulanate OR cefalexin with metronidazole 2, 1
   • For penicillin allergy: Ciprofloxacin plus metronidazole 2, 3, 4
   • Duration: 7-10 days 2

Complicated Diverticulitis

Defined by presence of abscess, phlegmon, fistula, obstruction, bleeding, or perforation 2

1. Inpatient management with IV antibiotics:

   • Ceftriaxone plus metronidazole
   • Piperacillin-tazobactam
   • Ampicillin/sulbactam 2, 1
   • For severe penicillin allergy: Aztreonam (1-2g every 8-12 hours) 2

2. Additional interventions based on complications:

   • Small abscesses (<4-5 cm): Antibiotic therapy alone
   • Large abscesses (≥4-5 cm): Percutaneous drainage plus antibiotics
   • Peritonitis or hemodynamic instability: Immediate surgical intervention 2

Monitoring and Follow-up

• Reassessment at 4-7 days to confirm symptom improvement 2
• Monitor for worsening symptoms:
  • Persistent/high fever
  • Worsening abdominal pain
  • Changes in bowel movements
  • Increasing abdominal distension
  • Worsening weakness or dizziness 2
• Colonoscopy recommended 4-6 weeks after resolution of complicated diverticulitis to rule out malignancy 2

Prevention

• High-fiber diet (fruits, vegetables, whole grains, legumes)
• Regular physical activity
• Smoking cessation
• Avoidance of regular NSAIDs, opiates, and corticosteroids 2

Treatment Success Rates

• Outpatient treatment success rates range from 92-97% 3, 4, 5
• Only 3-8% of outpatients require subsequent hospital admission 3, 4
• Postoperative mortality: 0.5% for elective colon resection vs. 10.6% for emergent colon resection 1

Special Considerations

• Elderly patients often present atypically, with only 50% having typical lower quadrant pain 2
• Approximately 5% of patients experience persistent abdominal pain with continued inflammation on CT scan 2
• Patients with penicillin allergy should be assessed for severity and treated accordingly; referral for penicillin allergy testing is recommended after failure of first-line therapy 2