Diverticulitis Classification and Treatment Approaches
Diverticulitis is most effectively classified using the WSES CT-guided classification system, which divides cases into uncomplicated and complicated categories, with treatment approaches tailored to disease severity ranging from outpatient management for uncomplicated cases to emergency surgery for peritonitis. 1
Classification Systems for Diverticulitis
Several classification systems exist for acute left colonic diverticulitis (ALCD), with the most prominent being:
1. Hinchey Classification (Traditional)
- Stage 1: Pericolic abscess
- Stage 2: Pelvic, intra-abdominal, or retroperitoneal abscess
- Stage 3: Generalized purulent peritonitis
- Stage 4: Fecal peritonitis
2. Modified Hinchey Classification (Kaiser et al., 2005)
- Stage 0: Mild clinical diverticulitis
- Stage 1a: Confined pericolic inflammation
- Stage 1b: Confined pericolic abscess
- Stage 2: Pelvic or distant intra-abdominal abscess
- Stage 3: Generalized purulent peritonitis
- Stage 4: Fecal peritonitis
3. WSES Classification (2015) - Most Recent and Comprehensive
- Uncomplicated: Diverticula, wall thickening, increased pericolic fat density
- Complicated:
- 1A: Pericolic air bubbles/small fluid without abscess
- 1B: Abscess ≤4 cm
- 2A: Abscess >4 cm
- 2B: Distant gas (>5 cm from inflamed segment)
- 3: Diffuse fluid without distant free gas
- 4: Diffuse fluid with distant free gas
Diagnostic Approach
CT scan with contrast is the gold standard for diagnosis of diverticulitis 1, 2. Diagnosis should include:
- Clinical history and physical examination (left lower quadrant pain/tenderness)
- Laboratory markers (elevated CRP, WBC)
- CT imaging to confirm diagnosis and classify severity
Treatment Algorithm Based on Classification
1. Uncomplicated Diverticulitis (WSES Stage 0)
- Outpatient management for clinically stable, afebrile patients 2
- Selective use of antibiotics - not routinely recommended as they don't reduce duration or prevent recurrence 2
- Dietary modifications and pain management
2. Complicated Diverticulitis with Small Abscess (WSES Stage 1B)
- Non-operative management with bowel rest 2
- Intravenous antibiotics covering gram-negative and anaerobic bacteria 3
- Close monitoring for clinical improvement
3. Complicated Diverticulitis with Large Abscess (WSES Stage 2A)
- Percutaneous drainage for abscesses >3-5 cm 2, 3
- Intravenous antibiotics
- Consider surgery if drainage fails or clinical deterioration occurs
4. Complicated Diverticulitis with Peritonitis (WSES Stages 3-4)
- Emergency surgical intervention 1, 2
- Fluid resuscitation and rapid antibiotic administration
- Surgical options:
- Hartmann procedure (resection with end colostomy)
- Primary anastomosis with or without diverting loop ileostomy
Follow-up Care
- Colonoscopy recommended 6 weeks after CT diagnosis for all patients with complicated diverticulitis 2
- Also recommended for patients with uncomplicated diverticulitis who have suspicious features on CT or meet bowel cancer screening criteria
Special Considerations
- Recurrent diverticulitis: Consider elective surgery after recovery, evaluated on a case-by-case basis 3, 4
- Emerging treatments: Mesalazine (alone or with antibiotics) and probiotics show promise in preventing recurrence 5
- Laparoscopic approach: Preferred for elective resections when technically feasible 4
Common Pitfalls to Avoid
- Overuse of antibiotics in uncomplicated cases
- Delayed drainage of large abscesses
- Failure to consider surgical intervention when non-operative management fails
- Missing underlying malignancy by skipping follow-up colonoscopy
- Overlooking organ dysfunction in patients with generalized peritonitis, which affects treatment approach and prognosis
The treatment approach should be guided by accurate classification of disease severity using CT findings, with management escalating from conservative measures to surgical intervention as severity increases 1, 2, 3.