In uncomplicated, left-sided acute diverticulitis, observation did not differ from antibiotics for recovery

Observation and antibiotics appeared to lead to similar time to recovery in patients with a first episode of uncomplicated, left-sided acute diverticulitis, according to a recent randomized controlled trial. Researchers at 22 surgical and gastroenterology centers in the Netherlands randomly assigned 570 patients to outpatient observation or antibiotics, usually amoxicillin-clavulanic acid started IV as an inpatient, 1200 mg four times daily for at least 48 hours, and switching to oral administration, 625 mg three times per day, if tolerated, for 10 days. The study's primary outcome was time to recovery, while secondary outcomes were hospital readmission; complicated, ongoing, and recurrent diverticulitis; sigmoid resection; and death. At 6-month follow-up, no differences were found in time to recovery, readmission, development of complications, or mortality between groups.

The study was published online Sept. 30, 2016, by the British Journal of Surgery. The following commentary by Anna C. Juncadella, MD, ACP Member, and Joseph D. Feuerstein, MD, was published in the ACP Journal Club section of the Feb. 21 Annals of Internal Medicine.

Most cases of diverticulitis are uncomplicated, with no significant long-term sequelae. Antibiotics have been the mainstay of therapy for diverticulitis, but the risk for adverse events (e.g., antibiotic resistance, Clostridium difficile infection) remains a concern. To date, only a few studies have evaluated antibiotics for diverticulitis. Based on these studies, the American Gastroenterological Association guideline suggests that antibiotics be used selectively in cases of uncomplicated diverticulitis and on an individual basis rather than routinely. The well-designed DIABOLO trial by Daniels and colleagues further supports that antibiotics are not always necessary in uncomplicated diverticulitis. In this trial, groups did not differ for time to recovery, readmission, complications, or mortality. Although these findings are interesting, they need to be considered in context. Group differences in outcomes were not statistically significant, but all showed a trend toward a benefit from antibiotics. Patients were from the Netherlands, and the median age was 56 to 57 years (interquartile range 48.5 to 64.6). Also, 21% of eligible patients declined to participate. Persuading patients that antibiotics are not necessary is often challenging, and evidence from additional trials and meta-analyses is still needed.

Although the findings of Daniels and colleagues provide additional evidence that a conservative approach might be feasible in mild diverticulitis, further multicentered and multinational studies, including both left- and right-sided diverticulitis, are needed to clarify which patients can be managed without antibiotics.