From the Guidelines
Antibiotic treatment should be reserved for patients with complicated diverticulitis or those with uncomplicated diverticulitis who have comorbidities, are frail, or have signs of systemic inflammation, as evidenced by a study published in Gastroenterology in 2021 1. The use of antibiotics in uncomplicated diverticulitis has been a topic of debate, with recent studies suggesting that they may not be necessary for all patients.
- A study published in the World Journal of Emergency Surgery in 2020 found that antibiotic treatment did not accelerate recovery or prevent complications in patients with uncomplicated diverticulitis 1.
- Another study published in the same journal in 2020 found that omitting antibiotics in patients with uncomplicated diverticulitis did not result in more complicated diverticulitis, recurrent diverticulitis, or sigmoid resections at long-term follow-up 1.
- The WSES/SICG/ACOI/SICUT/ACEMC/SIFIPAC guidelines for diagnosis and treatment of acute left colonic diverticulitis in the elderly, published in the World Journal of Emergency Surgery in 2022, suggest that antibiotic therapy should be avoided in immunocompetent elderly patients with uncomplicated left colonic diverticulitis without sepsis-related organ failures 1. For patients who require antibiotic treatment, the choice of antibiotic and duration of treatment should be based on the severity of the disease and the patient's individual characteristics.
- A study published in the Annals of Internal Medicine in 2022 found that the use of antibiotics in patients with acute uncomplicated left-sided colonic diverticulitis may not be necessary, and that outpatient management without antibiotics may be a viable option for select patients 1. It is essential to note that the decision to use antibiotics should be made on a case-by-case basis, taking into account the patient's overall health, the severity of the disease, and the presence of any underlying conditions that may affect the risk of complications.
- The American College of Physicians suggests that clinicians use abdominal CT imaging when there is diagnostic uncertainty in a patient with suspected acute left-sided colonic diverticulitis, and that most patients with acute uncomplicated left-sided colonic diverticulitis can be managed in an outpatient setting without antibiotics 1.
From the Research
Antibiotic Treatment for Diverticulitis
- The use of antibiotics in acute uncomplicated diverticulitis is a topic of debate, with some studies suggesting that it may not be necessary 2, 3.
- A study published in 2010 found that outpatient treatment with oral antibiotics was safe and effective for patients with uncomplicated acute diverticulitis 4.
- However, a systematic review published in 2022 found that the evidence for the use of antibiotics in uncomplicated diverticulitis is limited and of low quality, and that there may be little or no difference between antibiotics and no antibiotics in terms of short-term complications 2.
- Another study published in 2021 found that the use of antibiotics in acute uncomplicated diverticulitis could slightly increase complications and result in a minor or no difference in the risk of recurrence and need for urgent surgery 3.
- A comparative effectiveness study published in 2021 found that treating diverticulitis in the outpatient setting with amoxicillin-clavulanate may reduce the risk for fluoroquinolone-related harms without adversely affecting diverticulitis-specific outcomes 5.
- A study published in 2025 found that ceftriaxone and metronidazole was non-inferior to piperacillin/tazobactam for the treatment of complicated diverticulitis 6.
Types of Antibiotics Used
- The most commonly used antibiotics for diverticulitis include:
- Amoxicillin-clavulanate
- Ciprofloxacin plus metronidazole
- Ceftriaxone and metronidazole
- Piperacillin/tazobactam
- The choice of antibiotic may depend on the severity of the disease, the presence of comorbidities, and the risk of antibiotic resistance 4, 5, 6.