What is the initial management approach for diverticulitis?

Initial Management Approach for Diverticulitis

For select patients with acute uncomplicated left-sided colonic diverticulitis, initial management should focus on observation with supportive care (bowel rest and hydration) without antibiotics, while complicated diverticulitis requires more aggressive intervention based on the specific complications present. 1

Assessment and Classification

• Diverticulitis should be classified as either uncomplicated (localized inflammation) or complicated (associated with abscess, phlegmon, fistula, obstruction, bleeding, or perforation) to guide appropriate management 1
• CT scan is the recommended diagnostic test with 98-99% sensitivity and 99-100% specificity for confirming the diagnosis and determining the severity of diverticulitis 2
• Risk factors for progression to complicated disease include symptoms lasting >5 days, initial pain score >7, vomiting, systemic comorbidity, leukocyte count >13.5 × 10^9 cells/L, high C-reactive protein levels (>140 mg/L), and CT findings of pericolic extraluminal air or fluid collection 1

Management of Uncomplicated Diverticulitis

Outpatient vs. Inpatient Management

• Outpatient management is recommended for clinically stable patients with uncomplicated diverticulitis who can tolerate oral intake, have no significant comorbidities, and have adequate home support 1
• Low-certainty evidence shows no differences in risk for elective surgery or long-term diverticulitis recurrence between outpatient and inpatient management 1
• Outpatient management has lower associated costs (35-83% savings per episode) and reduces risks associated with hospitalization such as nosocomial infections 1, 3

Antibiotic Use in Uncomplicated Diverticulitis

• For immunocompetent patients with uncomplicated diverticulitis who have no systemic inflammatory response, antibiotics can be safely withheld 1
• Low-certainty evidence shows no differences in diverticulitis-related complications (abscess, fistula, stenosis, obstruction), quality of life, need for surgery, or long-term recurrence between patients treated with or without antibiotics 1, 4
• Antibiotic treatment may slightly decrease treatment failure rates (defined as "ongoing diverticulitis" within 3 months) compared to no antibiotic treatment 1, 5

When to Use Antibiotics in Uncomplicated Diverticulitis

• Antibiotics should be reserved for patients with:
  • Systemic symptoms (persistent fever or chills)
  • Increasing leukocytosis
  • Age >80 years
  • Pregnancy
  • Immunocompromised status
  • Chronic medical conditions (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 2
• First-line oral antibiotics include amoxicillin/clavulanic acid or cefalexin with metronidazole 2, 6
• For patients unable to tolerate oral intake, IV antibiotics (cefuroxime or ceftriaxone plus metronidazole or ampicillin/sulbactam) are appropriate 2

Management of Complicated Diverticulitis

Small Diverticular Abscess (<4-5 cm)

• Initial trial of non-operative treatment with antibiotics alone is recommended 1
• This approach has a pooled failure rate of 20% and mortality rate of 0.6% 1

Large Diverticular Abscess (>4-5 cm)

• Percutaneous drainage combined with antibiotic treatment is recommended 1
• When percutaneous drainage is not feasible, antibiotic therapy alone can be considered with careful clinical monitoring 1
• Surgical intervention should be performed if the patient shows worsening inflammatory signs or if the abscess does not respond to medical therapy 1

Peritonitis and Other Complications

• Patients with diffuse peritonitis require prompt fluid resuscitation, immediate antibiotic administration, and urgent surgical intervention 3
• For patients with CT findings of pericolic extraluminal gas, a trial of non-operative treatment with antibiotics is recommended 1, 3

Common Pitfalls and Caveats

• Failing to distinguish between uncomplicated and complicated diverticulitis can lead to inappropriate management 1
• Unnecessary use of antibiotics contributes to antibiotic resistance without providing significant clinical benefit in uncomplicated cases 1
• Initial management without antibiotics requires close monitoring and the ability to continue assessing patient status 1
• Patients with isolated pericolic gas may be suitable for non-operative treatment, but elevated CRP levels may predict treatment failure 1
• The traditional recommendation for colectomy after 2 episodes of diverticulitis is no longer universally accepted; decisions for elective resection should be individualized 3