What is the management approach for a patient with a first episode of diverticulitis (inflammation of the diverticula) and a 5-centimeter abscess?

From the Guidelines

For a patient with a first episode of diverticulitis and a 5 cm abscess, I recommend percutaneous drainage of the abscess along with broad-spectrum antibiotics. This approach is supported by the most recent guidelines, including the 2023 WSES, GAIS, SIS-E, SIS-A guidelines 1, which suggest that adequate source control for complicated acute left colon diverticulitis stage 1 or 2a consists of percutaneous drainage combined with antibiotic therapy for larger diverticular abscesses.

Management Approach

• Start with intravenous antibiotics such as piperacillin-tazobactam 3.375g every 6 hours or a combination of ciprofloxacin 400mg every 12 hours plus metronidazole 500mg every 8 hours.
• Arrange for CT-guided percutaneous drainage as soon as possible, as abscesses larger than 3-4 cm generally require drainage.
• Once the patient shows clinical improvement (decreased pain, fever resolution, normalized white blood cell count), transition to oral antibiotics such as amoxicillin-clavulanate 875/125mg twice daily or ciprofloxacin 500mg twice daily plus metronidazole 500mg three times daily.
• Continue antibiotics for a total of 10-14 days.
• The patient should remain NPO initially, with gradual diet advancement as symptoms improve.

Follow-Up and Prevention

• After resolution of the acute episode, schedule a colonoscopy in 6-8 weeks to exclude malignancy.
• Consider elective sigmoid resection after the patient has fully recovered, particularly given the complicated nature of this first episode with a large abscess, as there is a higher risk of recurrence or complications with subsequent episodes, as noted in the 2020 update of the WSES guidelines for the management of acute colonic diverticulitis in the emergency setting 1.

This approach combines source control through drainage with appropriate antimicrobial therapy to effectively manage the infection while minimizing the risks associated with emergency surgery during active inflammation.

From the FDA Drug Label

INTRA‑ABDOMINAL INFECTIONS, including peritonitis, intra‑abdominal abscess, and liver abscess, caused by Bacteroides species including the B. fragilis group In amebic liver abscess, metronidazole tablet therapy does not obviate the need for aspiration or drainage of pus. The patient with a first episode of diverticulitis and a 5 cm abscess should be managed with antibiotic therapy and consideration of drainage of the abscess. Metronidazole may be used as part of the antibiotic regimen, but the decision to use it should be based on the suspected or confirmed causative bacteria. The presence of a 5 cm abscess may require aspiration or drainage in addition to antibiotic therapy 2.

• Key considerations:
  • Antibiotic therapy should be targeted at the suspected or confirmed causative bacteria
  • Drainage of the abscess may be necessary
  • Metronidazole may be used as part of the antibiotic regimen, but its use should be guided by culture and susceptibility results or local epidemiology and susceptibility patterns.

From the Research

Management of Diverticulitis with a 5 cm Abscess

• The management of diverticulitis with a 5 cm abscess can be approached through conservative treatment with broad-spectrum antibiotics, as suggested by 3, which has been shown to be successful in up to 70% of cases.
• According to 4, larger abscesses of 3-5 cm should be drained percutaneously, but selected patients can be initially treated with antibiotics without adverse consequences on their outcomes, as found in 5.
• The decision to proceed with percutaneous drainage or antibiotics alone should be based on patient characteristics, disease severity, and surgeon preference, as discussed in 5.
• It is essential to note that patients with peritonitis and sepsis should receive fluid resuscitation, rapid antibiotic administration, and urgent surgery, as recommended by 4.

Treatment Options

• Antibiotics play a key role in the management of both uncomplicated and complicated diverticulitis, as stated in 3.
• The use of broad-spectrum antibiotics, such as metronidazole-with-fluoroquinolone or amoxicillin-clavulanate, can be effective in treating diverticulitis, but the comparative effectiveness of these antibiotics is uncertain, as discussed in 6.
• Amoxicillin-clavulanate may reduce the risk for fluoroquinolone-related harms without adversely affecting diverticulitis-specific outcomes, as suggested by 6.

Patient Evaluation and Follow-up

• Computed tomography (CT) is necessary to diagnose the first occurrence of diverticulitis and to assess the severity of symptoms, as recommended by 4.
• 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, as stated in 4.