What is the management approach for diverticulitis?

Management of Diverticulitis

For immunocompetent patients with uncomplicated diverticulitis, observation with supportive care alone—without antibiotics—is the recommended first-line approach, reserving antibiotics only for those with specific high-risk features. 1, 2, 3

Diagnosis and Classification

Diagnostic Imaging:

• CT scan with oral and IV contrast is the gold standard, with 98-99% sensitivity and 99-100% specificity 2, 4, 5
• CT findings include colonic wall thickening, increased density of pericolic fat, and in complicated cases: abscess, free fluid, extraluminal gas, or perforation 3
• Point-of-care ultrasound can identify wall thickening and complications in patients unable to undergo CT 3

Classification:

• Uncomplicated diverticulitis: Localized inflammation without abscess, perforation, fistula, obstruction, or bleeding 1, 2, 6
• Complicated diverticulitis: Inflammation with abscess, phlegmon, fistula, obstruction, bleeding, or perforation—occurs in approximately 12-15% of cases 1, 2

Treatment of Uncomplicated Diverticulitis

When to Avoid Antibiotics

Most immunocompetent patients with uncomplicated diverticulitis do NOT require antibiotics. Multiple high-quality randomized trials, including the DIABOLO trial with 528 patients, demonstrate that antibiotics neither accelerate recovery nor prevent complications or recurrence 2, 3, 4

Outpatient management without antibiotics is appropriate when patients:

• Can tolerate oral fluids and medications 2, 7
• Have no significant comorbidities or frailty 2, 7
• Have adequate home support 2, 7
• Are afebrile with stable vital signs 2, 5
• Have no signs of systemic inflammation 2, 3

Supportive care consists of:

• Clear liquid diet during acute phase, advancing as symptoms improve 2, 7
• Pain control with acetaminophen (avoid NSAIDs) 2, 4
• Bowel rest 2, 6
• Re-evaluation within 7 days, or sooner if clinical deterioration 2, 3, 7

When Antibiotics ARE Indicated

Reserve antibiotics for patients with ANY of these high-risk features:

Systemic/Clinical Indicators:

• Persistent fever or chills despite supportive care 2, 4
• Increasing leukocytosis (WBC >15 × 10⁹ cells/L) 1, 2, 4
• Elevated CRP >140 mg/L 2, 7
• Refractory symptoms or vomiting 2, 7
• Inability to maintain oral hydration 2, 7
• Symptoms lasting >5 days prior to presentation 2, 7
• Severe pain score (≥8/10) 2

Patient-Specific Risk Factors:

• Immunocompromised status (chemotherapy, high-dose steroids, organ transplant) 1, 2, 4
• Age >80 years 2, 4
• Pregnancy 2, 4
• Significant comorbidities (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) 2, 4
• ASA score III or IV 2, 7

CT Imaging Features:

• Fluid collection or abscess 1, 2, 7
• Longer segment of inflammation 1, 2, 7
• Pericolic extraluminal air 2, 7

Antibiotic Regimens

Outpatient Oral Therapy (4-7 days for immunocompetent patients):

• First-line: Ciprofloxacin 500 mg PO twice daily PLUS metronidazole 500 mg PO three times daily 1, 2, 7, 4
• Alternative: Amoxicillin-clavulanate 875/125 mg PO twice daily 2, 7, 4

Inpatient IV Therapy:

• Ceftriaxone PLUS metronidazole 2, 7, 4
• Piperacillin-tazobactam 2, 7, 4
• Cefuroxime PLUS metronidazole 7, 4
• Ampicillin-sulbactam 7, 4
• Transition to oral antibiotics as soon as patient tolerates oral intake to facilitate earlier discharge 2, 3, 7

Duration of Therapy:

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

Hospitalization Criteria

Admit patients with:

• Complicated diverticulitis 2, 3, 7
• Inability to tolerate oral intake 2, 3, 7
• Severe pain or systemic symptoms (sepsis, septic shock) 2, 3, 4
• Significant comorbidities or frailty 2, 3, 7
• Immunocompromised status 2, 3, 7
• Signs of peritonitis 2, 5, 6

Treatment of Complicated Diverticulitis

All patients with complicated diverticulitis require antibiotics and hospitalization. 2, 3, 4

Abscess Management

Small abscesses (<4-5 cm):

• IV antibiotics alone for 7 days 2, 3, 5

Large abscesses (≥4-5 cm):

• Percutaneous CT-guided drainage PLUS IV antibiotics for 4 days 2, 3, 7, 5
• Cultures from drainage guide antibiotic selection 7

Generalized peritonitis or sepsis:

• Emergent surgical consultation 2, 3, 4
• IV fluid resuscitation 2, 5
• Broad-spectrum IV antibiotics (piperacillin-tazobactam, meropenem, or ceftriaxone plus metronidazole) 2, 7, 4
• Emergent laparotomy with colonic resection 2, 4, 5

Surgical Options

For generalized peritonitis:

• Primary resection with anastomosis (in stable patients) 2
• Hartmann procedure (in critically ill patients with diffuse peritonitis) 2, 5
• Laparoscopic peritoneal lavage is NOT recommended 2

Mortality rates:

• Elective colon resection: 0.5% 4
• Emergent colon resection: 10.6% 4

Prevention of Recurrence

Dietary and Lifestyle Modifications:

• High-quality diet: High in fiber from fruits, vegetables, whole grains, legumes (>22.1 g/day); low in red meat and sweets 1, 2, 3
• Regular vigorous physical activity 1, 2, 3
• Achieve or maintain normal BMI (18-25 kg/m²) 2, 3
• Smoking cessation 2, 3
• Avoid regular use of NSAIDs and opioids 1, 2, 3

What NOT to restrict:

• Nuts, corn, popcorn, and small-seeded fruits are NOT associated with increased risk and should NOT be restricted 1, 2, 3

Medications to AVOID for prevention:

• Mesalamine: Strong recommendation AGAINST use 1, 2
• Rifaximin: Conditional recommendation against use 1, 2
• Probiotics: Conditional recommendation against use 1

Follow-Up and Colonoscopy

Colonoscopy is recommended 4-6 weeks after resolution for:

• All patients with complicated diverticulitis (7.9% risk of colon cancer) 2
• Patients with uncomplicated diverticulitis who have suspicious CT features 2, 5, 6
• Patients >50 years requiring age-appropriate screening 2
• Overall risk of colorectal cancer in diverticulitis patients: 1.16% 2

Surgical Considerations for Recurrent Disease

Elective surgery should NOT be based solely on number of episodes. 1, 2

The traditional "two-episode rule" is no longer accepted. Decision for elective resection should be based on: 2

• Quality of life impact 2
• Frequency of recurrence 2
• Patient preferences 1, 2
• Operative risks and comorbidities 1, 2

Evidence from DIRECT trial: Elective sigmoidectomy results in significantly better quality of life at 6 months compared to continued conservative management in patients with recurrent/persistent symptoms 2

Recurrence rates:

• Without surgery: 61% at 5 years 2
• With surgery: 15% at 5 years (surgery reduces but does not eliminate recurrence) 2

Surgical complications:

• Short-term complications (wound infection, anastomotic leak, cardiovascular events): 10% 1
• Long-term complications (abdominal distention, cramping, altered defecation, fecal incontinence): 25% 1

Common Pitfalls to Avoid

• Overusing antibiotics in uncomplicated diverticulitis without risk factors—contributes to antibiotic resistance without clinical benefit 1, 2
• Applying the "no antibiotics" approach to Hinchey 1b/2 or higher disease—the evidence specifically excluded these patients 2
• Assuming all patients require hospitalization—most can be safely managed as outpatients with 35-83% cost savings 1, 2
• Unnecessarily restricting nuts, seeds, and popcorn—not evidence-based and may reduce overall fiber intake 1, 2
• Stopping antibiotics early when they ARE indicated, even if symptoms improve 2
• Failing to recognize high-risk features that predict progression to complicated disease 1, 2
• Delaying surgical consultation in patients with frequent recurrence affecting quality of life 2
• Prescribing mesalamine or rifaximin for prevention—no proven benefit 1, 2