What is the management plan for diverticulitis?

Management of Diverticulitis

For immunocompetent patients with uncomplicated diverticulitis, observation without antibiotics is the recommended first-line approach, reserving antibiotics only for those with systemic symptoms, immunocompromise, advanced age, or specific high-risk features. 1, 2, 3

Initial Assessment and Risk Stratification

When evaluating a patient with suspected diverticulitis, obtain:

• Complete blood count and C-reactive protein to assess for leukocytosis (WBC >15 × 10^9/L) and elevated inflammatory markers (CRP >140 mg/L) 1, 2
• CT scan with contrast (sensitivity 98-99%, specificity 99-100%) to confirm diagnosis and identify complications 4
• CT findings predicting complicated disease: pericolic extraluminal air, fluid collections, or longer segments of inflammation 1, 3

Classification

• Uncomplicated diverticulitis (85% of cases): Localized inflammation without abscess, perforation, fistula, or obstruction 4, 5
• Complicated diverticulitis: Presence of abscess, perforation, fistula, obstruction, or generalized peritonitis 2, 4

Treatment Algorithm for Uncomplicated Diverticulitis

Step 1: Determine Need for Antibiotics

Most immunocompetent patients do NOT require antibiotics. 1, 2, 3 Multiple high-quality trials demonstrate no benefit in recovery time, complication rates, or recurrence with routine antibiotic use. 1

Reserve antibiotics for patients with:

• Immunocompromised status (chemotherapy, high-dose steroids, organ transplant) 1, 2, 4
• Age >80 years 1, 2, 4
• Persistent fever or chills 1, 4
• Increasing leukocytosis or WBC >15 × 10^9/L 1, 2, 3
• CRP >140 mg/L 1, 2, 3
• Refractory symptoms or vomiting 1, 2
• Fluid collection or longer segment of inflammation on CT 1, 2, 3
• Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 1, 4
• Pregnancy 1, 4

Step 2: Outpatient vs. Inpatient Management

Outpatient management is appropriate when:

• Patient can tolerate oral fluids and medications 1, 2, 3
• No significant comorbidities or frailty 1, 2
• Adequate home support 1, 2
• Temperature <100.4°F 3
• Pain score <4/10 controlled with acetaminophen 3

Hospitalization required for:

• Complicated diverticulitis 2, 4
• Inability to tolerate oral intake 1, 2
• Severe pain or systemic symptoms 2
• Signs of peritonitis 5
• Sepsis or septic shock 1, 4

Step 3: Supportive Care (All Patients)

• Clear liquid diet during acute phase, advancing as symptoms improve 1, 2
• Pain control with acetaminophen (avoid NSAIDs and opioids as they increase diverticulitis risk) 6, 4
• Mandatory re-evaluation within 7 days; earlier if clinical deterioration 1, 2, 3

Antibiotic Regimens When Indicated

Outpatient Oral Regimens (4-7 days for immunocompetent patients)

First-line options:

• Amoxicillin-clavulanate 875/125 mg orally twice daily 1, 3, 4
• Ciprofloxacin 500 mg orally twice daily PLUS metronidazole 500 mg orally three times daily 1, 3, 4

Inpatient IV Regimens

Initial IV therapy:

• Ceftriaxone PLUS metronidazole 1, 4
• Cefuroxime PLUS metronidazole 1
• Piperacillin-tazobactam 1, 4
• Ampicillin-sulbactam 1, 4

Transition to oral antibiotics as soon as patient tolerates oral intake to facilitate earlier discharge (hospital stays are shorter with observation: 2 vs 3 days). 1, 3

Duration of Therapy

• Immunocompetent patients: 4-7 days 1, 2, 3
• Immunocompromised or critically ill patients: 10-14 days 1, 3
• Post-surgical with adequate source control: 4 days 1, 3

Management of Complicated Diverticulitis

Abscess Management

• Small abscesses (<4-5 cm): Antibiotics alone for 7 days 1, 2
• Large abscesses (≥4-5 cm): Percutaneous drainage PLUS antibiotics for 4 days 1, 2, 4

Surgical Indications

• Emergent surgery: Generalized peritonitis, free perforation 4, 5
• Elective surgery consideration: Recurrent episodes significantly impacting quality of life (the traditional "two-episode rule" is outdated) 3
• Mortality rates: 0.5% for elective resection vs 10.6% for emergent resection 4

Prevention of Recurrence

Dietary and Lifestyle Modifications

• High-fiber diet (>22 g/day from fruits, vegetables, whole grains, legumes) 6, 3
• Regular vigorous physical activity 6, 3
• Achieve/maintain normal BMI 6, 3
• Smoking cessation 3, 5

What NOT to Restrict

Do NOT advise patients to avoid nuts, popcorn, corn, or small-seeded fruits – these are not associated with increased diverticulitis risk. 6, 2, 3

Medications to Avoid

• Avoid NSAIDs when possible (associated with increased diverticulitis risk) 6, 3
• Avoid opioids (associated with increased risk) 3, 4
• Aspirin can be continued (no need to routinely discontinue) 6

Medications NOT Recommended for Prevention

Do NOT prescribe:

• Mesalamine (strong recommendation against) 6
• Rifaximin 6
• Probiotics 6

Critical Pitfalls to Avoid

• Overusing antibiotics in uncomplicated cases without risk factors – provides no benefit and contributes to resistance 1, 2, 3
• Failing to recognize high-risk patients who need antibiotics despite having uncomplicated disease (immunocompromised, elderly, high inflammatory markers) 2, 3
• Assuming all patients require hospitalization when 95% can be safely managed outpatient with appropriate follow-up 2, 7
• Stopping antibiotics early even if symptoms improve – complete the full course 3
• Delaying surgical consultation in patients with frequent recurrences significantly impacting quality of life 3
• Restricting nuts, seeds, and popcorn unnecessarily – this outdated advice lacks evidence 6, 2, 3

Special Populations

Immunocompromised Patients

• Lower threshold for CT imaging, antibiotics, and surgical consultation 1, 3
• Extended antibiotic duration (10-14 days) 1, 3
• Higher risk for perforation and mortality 3, 4

Elderly Patients (>80 years)

• Antibiotics recommended even for uncomplicated disease 1, 2, 4
• Higher operative risks but also higher risk of complications without treatment 6

Pregnant Patients

• Antibiotics indicated 1, 4
• Close monitoring required 3