What is the management and treatment for diverticulitis?

Management and Treatment of Diverticulitis

Initial Diagnostic Approach

For patients with suspected acute diverticulitis, obtain a contrast-enhanced CT scan of the abdomen and pelvis, which has 98-99% sensitivity and 99-100% specificity for diagnosis. 1, 2 This imaging is essential to differentiate uncomplicated from complicated disease and guide treatment decisions.

Key CT Findings to Assess:

• Uncomplicated diverticulitis: Localized inflammation, wall thickening, pericolic fat stranding without abscess, perforation, fistula, or obstruction 1, 3
• Complicated diverticulitis: Presence of abscess, phlegmon, perforation, fistula, obstruction, or free air 1, 3
• High-risk CT features: Pericolic extraluminal air, fluid collection, or longer inflamed colon segment predict progression to complicated disease 1, 3

Laboratory Assessment:

• Complete blood count, C-reactive protein, and basic metabolic panel 1, 2
• CRP >140 mg/L or WBC >15 × 10⁹ cells/L indicate higher risk requiring antibiotic therapy 3, 4

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Treatment of Uncomplicated Diverticulitis

First-Line Management: Observation Without Antibiotics

For immunocompetent patients with uncomplicated diverticulitis, manage with observation, clear liquid diet, and acetaminophen for pain control—antibiotics are NOT routinely necessary. 1, 3, 4 Multiple high-quality randomized trials, including the DIABOLO trial with 528 patients, demonstrate that antibiotics neither accelerate recovery nor prevent complications or recurrence in this population. 3, 4

Outpatient vs. Inpatient Decision:

Manage most patients with uncomplicated diverticulitis as outpatients when they meet these criteria: 1, 3

• Can tolerate oral fluids and medications
• Temperature <100.4°F
• Pain score <4/10 (controlled with acetaminophen)
• No significant comorbidities or frailty
• Adequate home support and ability to maintain self-care

Hospitalize patients with: 1, 3, 2

• Complicated diverticulitis
• Inability to tolerate oral intake
• Systemic inflammatory response or sepsis
• Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes)
• Immunocompromised status
• Age >80 years with systemic symptoms

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Selective Antibiotic Use in Uncomplicated Diverticulitis

Indications for Antibiotics:

Reserve antibiotics for patients with specific high-risk features: 3, 4, 2

• Immunocompromised status (chemotherapy, high-dose steroids, organ transplant recipients)
• Persistent fever or chills despite supportive care
• Increasing leukocytosis or WBC >15 × 10⁹ cells/L
• Elevated CRP >140 mg/L
• Age >80 years
• Pregnancy
• Symptoms >5 days duration before presentation
• Persistent vomiting or inability to maintain hydration
• ASA score III or IV
• CT findings: Fluid collection or longer segment of inflammation

Antibiotic Regimens When Indicated:

Outpatient oral regimens (4-7 days): 3, 4, 5

• First-line: Amoxicillin-clavulanate 875/125 mg orally twice daily
• Alternative: Ciprofloxacin 500 mg orally twice daily PLUS metronidazole 500 mg orally three times daily

Inpatient IV regimens: 3, 5, 2

• Ceftriaxone PLUS metronidazole
• Cefuroxime PLUS metronidazole
• Piperacillin-tazobactam
• Ampicillin-sulbactam

Duration of therapy: 3, 5

• 4-7 days for immunocompetent patients
• 10-14 days for immunocompromised patients
• Transition to oral antibiotics as soon as patient tolerates oral intake to facilitate earlier discharge

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Treatment of Complicated Diverticulitis

Abscess Management:

Small abscesses (<4-5 cm): 3, 4, 5

• IV antibiotics alone for 7 days
• Gram-negative and anaerobic coverage (ceftriaxone plus metronidazole or piperacillin-tazobactam)

Large abscesses (≥4-5 cm): 3, 4, 5

• Percutaneous CT-guided drainage PLUS IV antibiotics for 4 days (with adequate source control)
• Cultures from drainage guide antibiotic selection

Surgical Indications:

Emergent surgical consultation required for: 3, 2, 6

• Generalized peritonitis
• Sepsis or septic shock
• Failed medical management or percutaneous drainage
• Free perforation with diffuse peritonitis

Surgical options: 2, 6

• Primary resection with anastomosis (preferred in stable patients)
• Hartmann procedure (for critically ill patients with diffuse peritonitis)
• Elective sigmoidectomy mortality: 0.5%
• Emergent resection mortality: 10.6%

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Follow-Up and Monitoring

Re-evaluate all patients within 7 days; earlier if clinical deterioration occurs. 3, 4 Watch for warning signs requiring immediate attention: fever >101°F, severe uncontrolled pain, persistent vomiting, inability to eat/drink, or signs of dehydration. 3

Colonoscopy Recommendations:

Perform colonoscopy 4-6 weeks after resolution for: 3, 2, 6

• All patients with complicated diverticulitis
• First episode of uncomplicated diverticulitis in patients >50 years
• Suspicious CT features suggesting possible malignancy
• Patients meeting age-appropriate screening criteria

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Prevention of Recurrence

Lifestyle Modifications:

Implement these evidence-based strategies to reduce recurrence risk: 3, 2, 7

• High-quality diet: High in fiber from fruits, vegetables, whole grains, legumes (>22.1 g/day); low in red meat and sweets
• Regular vigorous physical activity
• Achieve or maintain normal BMI
• Smoking cessation
• Avoid regular use of NSAIDs and opioids when possible (associated with increased diverticulitis risk)

Do NOT restrict nuts, corn, popcorn, or small-seeded fruits—these are not associated with increased diverticulitis risk. 3, 4

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Elective Surgery Considerations

Do NOT base surgical decisions on number of episodes alone. 3 The traditional "two-episode rule" is no longer accepted. Instead, individualize decisions based on: 3

• Quality of life impact
• Frequency and severity of recurrences
• Patient age and comorbidities
• Risk of complicated disease

The DIRECT trial demonstrated that elective sigmoidectomy results in significantly better quality of life at 6 months compared to continued conservative management in patients with recurrent/persistent symptoms. 3 However, surgery reduces but does not eliminate recurrence risk (15% at 5 years with surgery vs. 61% with conservative management). 3

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Critical Pitfalls to Avoid

• Do NOT routinely prescribe antibiotics for immunocompetent patients with uncomplicated diverticulitis without risk factors—this provides no benefit and contributes to antibiotic resistance 3, 4
• Do NOT assume all patients require hospitalization—outpatient management is safe and cost-effective (35-83% cost savings per episode) for appropriate candidates 1, 3
• Do NOT stop antibiotics early if they are indicated, even if symptoms improve 3
• Do NOT apply the "no antibiotics" approach to complicated diverticulitis (Hinchey 1b or higher) or immunocompromised patients 3, 4
• Do NOT delay surgical consultation in patients with frequent recurrences significantly impacting quality of life 3
• Do NOT unnecessarily restrict diet with avoidance of nuts, seeds, or popcorn—this is not evidence-based 3, 4