Antibiotics Overused for Uncomplicated Diverticulitis Despite Guideline Recommendations: Study
Researchers have found in a large study of more than 33,000 emergency department and urgent care visits from 2015-2025 that antibiotics were prescribed in nearly all cases of uncomplicated diverticulitis, despite guidelines recommending selective rather than routine use. Antibiotic prescribing rates remained consistently high throughout the decade across healthcare facilities. The most commonly prescribed treatments were fluoroquinolone-based regimens and amoxicillin-clavulanate, with prescribing patterns gradually shifting toward amoxicillin-clavulanate over time due to growing concerns about fluoroquinolone safety. However, this change did not significantly reduce overall antibiotic use. The study was published in Annals of Internal Medicine journal by Sutton JD and colleagues.
In order to quantify the precise trends of antibiotic usage for this prevalent colon disease, investigators conducted a large-scale retrospective cohort study analyzing the health records of VA centers in the US. A research team assessed the medical data of patients in a ten-year time frame starting from 2015 until 2025. The research paid close attention to visits at the emergency departments and urgent cares for patients that have been diagnosed with acute uncomplicated diverticulitis either as a primary or a secondary condition.
To create an extremely accurate cohort sample, researchers removed people who did not undergo an objective CT examination, those who needed hospitalization within 24 hours from their visit to the ED and UC, as well as those with the history of diverticulitis in the past 90 days. The first outcome variable that was used in the study included the prescription of an antibiotic during the same or the next day after the outpatient visit while the second outcome was the class of the antibiotic prescribed to patients.
Key findings:
- The retrospective study managed to record and analyze 33,634 visits made by individual patients seeking treatment for uncomplicated diverticulitis at either the emergency department or urgent care.
- These records were collected from the aggregated sample population of 28,474 unique individual patients at 120 national VA medical facilities.
- The antibiotics were astonishingly prescribed at 96.6% frequency, where the rate of prescription remained high over the years and consistently failed to drop below 95.6% even once between 2015 and 2025.
- This unique population had a median age of 63 years with a median body mass index of 30.6, consisting of 90% males, 75% white, 20% Black, and 11% Hispanic.
- A majority of these patients were otherwise healthy and did not have the systemic problems associated with the use of antibiotics, where only 20% were smokers, 2% were diabetic with complications, 3% were frail or demented patients, and a median Charlson Comorbidity Index of 0.
- High-risk fluoroquinolone-based antibiotic regimens were commonly chosen throughout the ten-year study period, accounting for 45.6% of all fills.
- Amoxicillin-clavulanate regimen was chosen as the second most popular one at 42.7%.
- It is noteworthy that Amoxicillin-clavulanate regimen replaced the fluoroquinolones in terms of preference by 2025.
These findings highlight a persistent gap between evidence-based guidelines and clinical practice, underscoring the need for stronger antibiotic stewardship initiatives to promote appropriate, selective antibiotic use in uncomplicated diverticulitis. Limitations of the study include the potential misclassification of cases and inaccuracies in prescription records.
Reference:
Sutton, J. D., Westanmo, A. D., Gravely, A. A., Geurkink, E. A., Drekonja, D. M., & Peterson, K. L. (2026). Outpatient Antibiotic Prescribing for Uncomplicated Diverticulitis in Veterans Affairs Facilities: A Retrospective Cohort Study. Annals of Internal Medicine. https://doi.org/10.7326/annals-25-05583
