What is the initial workup and treatment for a patient presenting with diverticulitis?

From the Guidelines

The initial workup for suspected diverticulitis includes a thorough history and physical examination, complete blood count to assess for leukocytosis, C-reactive protein, and imaging with CT scan of the abdomen and pelvis with IV contrast to confirm diagnosis and assess severity. For uncomplicated diverticulitis (no abscess, perforation, or peritonitis), outpatient management is appropriate with selective use of oral antibiotics, such as amoxicillin-clavulanate 875/125 mg twice daily for 7-10 days, or alternatively ciprofloxacin 500 mg twice daily plus metronidazole 500 mg three times daily for the same duration, based on patient-specific factors and clinical judgment 1. Patients should maintain a clear liquid diet initially, gradually advancing as symptoms improve, and use acetaminophen for pain control while avoiding NSAIDs and opioids if possible.

Key Considerations

• The use of antibiotics can be selective, rather than routine, in immunocompetent patients with mild uncomplicated diverticulitis 1.
• Patients with significant comorbidities, severe pain, inability to tolerate oral intake, or signs of sepsis require hospitalization for IV antibiotics, bowel rest, IV fluids, and possible surgical consultation.
• Percutaneous drainage may be needed for abscesses larger than 4 cm.
• The management approach should be individualized based on the patient's clinical presentation, disease severity, and risk factors for complications.

Diagnostic Approach

• CT scan of the abdomen and pelvis with IV contrast is the preferred imaging modality for diagnosing diverticulitis and assessing its severity 1.
• Clinical considerations, such as the presence of systemic inflammatory response, immunosuppression, or signs of sepsis, should guide the decision to use antibiotics or proceed with surgical consultation.

Treatment Principles

• Outpatient management is suitable for most patients with uncomplicated diverticulitis, with selective use of antibiotics and supportive care 1.
• Hospitalization is necessary for patients with complicated diverticulitis, significant comorbidities, or severe symptoms.
• The goal of treatment is to manage symptoms, prevent complications, and improve quality of life, while minimizing the risk of antibiotic resistance and other adverse effects.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Initial Workup for Diverticulitis

• The initial workup for diverticulitis typically involves radiological evidence of inflammation using computed tomography (CT) to diagnose the first occurrence of diverticulitis 2.
• CT is also warranted when the severity of symptoms suggests that perforation or abscesses have occurred 2.
• Diverticulitis is classified as complicated or uncomplicated based on CT scan, severity of symptoms, and patient history; this classification is used to direct management 2.

Treatment for Uncomplicated Diverticulitis

• Outpatient treatment is recommended in afebrile, clinically stable patients with uncomplicated diverticulitis 2, 3.
• Antibiotics have no proven benefit in reducing the duration of the disease or preventing recurrence in patients with uncomplicated diverticulitis and should only be used selectively 2, 4.
• Ambulatory treatment with oral antibiotics, such as amoxicillin-clavulanic or ciprofloxacin plus metronidazole, can be safe and effective for patients with uncomplicated diverticulitis who can tolerate oral intake and have adequate family support 3.

Treatment for Complicated Diverticulitis

• Non-operative management, including bowel rest and intravenous antibiotics, is indicated for small abscesses 2.
• Larger abscesses of 3-5 cm should be drained percutaneously 2.
• Patients with peritonitis and sepsis should receive fluid resuscitation, rapid antibiotic administration, and urgent surgery 2.
• Surgical intervention with either Hartmann procedure or primary anastomosis, with or without diverting loop ileostomy, is indicated for peritonitis or in failure of non-operative management 2.

Follow-up and Colonoscopy

• Colonoscopy is recommended for all patients with complicated diverticulitis 6 weeks after CT diagnosis of inflammation, and for patients with uncomplicated diverticulitis who have suspicious features on CT scan or who otherwise meet national bowel cancer screening criteria 2.