What are the diagnosis and treatment options for diverticulitis?

Diagnosis and Treatment of Diverticulitis

CT scanning with IV contrast is the gold standard for diagnosing diverticulitis, with antibiotics reserved for complicated cases or patients with specific risk factors, while uncomplicated diverticulitis can be managed conservatively without antibiotics in most cases. 1, 2

Diagnosis

Clinical Presentation

• Left lower quadrant abdominal pain (most common presentation)
• Fever, nausea, vomiting
• Leukocytosis and elevated inflammatory markers (CRP)
• Note: In elderly patients (>65 years), only 50% present with typical lower quadrant pain, 17% have fever, and 43% do not have leukocytosis 1

Risk Factors for Diverticulitis

• Age >65 years
• Obesity (BMI ≥30)
• Use of medications: opioids, corticosteroids, NSAIDs
• Genetic factors and connective tissue diseases
• Hypertension and type 2 diabetes 3

Diagnostic Imaging

• CT scan with IV contrast is the recommended first-line imaging modality:

  • Sensitivity: 98-99%
  • Specificity: 99-100% 2, 3
  • Should be performed in all elderly patients with suspected diverticulitis regardless of laboratory values 1

• Alternative imaging when CT with contrast is contraindicated:

  • Ultrasound (sensitivity 90%, specificity 90-100%)
  • MRI
  • CT without contrast 1

Classification

Diverticulitis is classified as:

1. Uncomplicated diverticulitis: Localized inflammation without abscess, perforation, fistula, or obstruction (85% of cases) 3
2. Complicated diverticulitis: Presence of abscess, perforation, fistula, obstruction, or bleeding

Treatment Approach

Uncomplicated Diverticulitis

• Conservative management without antibiotics is recommended for stable patients with minimal comorbidities 2
• Pain control (acetaminophen preferred over NSAIDs)
• Clear liquid diet initially, advancing as tolerated
• Outpatient treatment for afebrile, clinically stable patients 4

Antibiotic Therapy

Antibiotics should be reserved for patients with:

• Systemic symptoms (persistent fever, chills)
• Increasing leukocytosis
• Age >80 years
• Pregnancy
• Immunocompromised status (chemotherapy, high-dose steroids, organ transplant)
• Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 2, 3

Antibiotic Options:

• Oral regimens: Amoxicillin/clavulanic acid or cefalexin with metronidazole
• IV regimens: Ceftriaxone plus metronidazole, piperacillin-tazobactam, or ampicillin/sulbactam 3
• Duration: 5-7 days 2

Complicated Diverticulitis

• Small abscesses (<4-5 cm): Antibiotic therapy alone
• Large abscesses (≥4-5 cm): Percutaneous drainage plus antibiotics 2
• Peritonitis: Surgical intervention with antibiotic therapy
• Hemodynamically unstable patients: Damage control surgery 2

Surgical Indications

• Peritonitis
• Large abscesses not responding to percutaneous drainage
• Fistula formation
• Bowel obstruction
• Recurrent episodes of diverticulitis 2

Predictors of Disease Progression

Factors suggesting potential progression to complicated disease:

• Symptoms lasting >5 days
• Initial pain score >7
• Vomiting
• Systemic comorbidity
• Leukocyte count >13.5 × 10^9 cells/L
• CRP >140 mg/L
• CT findings of pericolic extraluminal air or fluid collection 1, 2

Prevention of Recurrence

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

Follow-up

• Colonoscopy recommended 4-6 weeks after resolution of complicated diverticulitis to rule out malignancy 2, 4
• Monitor for treatment failure (persistent or worsening symptoms)

Special Considerations

• Elderly patients: Lower threshold for CT imaging and antibiotic therapy due to atypical presentation and higher risk of complications 1
• Immunocompromised patients: Higher risk of complications; more aggressive treatment approach warranted 2