Conservative treatment of acute colonic diverticulitis: are antibiotics always mandatory?

Most patients admitted for acute colonic diverticulitis (AD) are managed conservatively and receive antibiotics, although it is uncertain whether all patients with AD benefit from this treatment. The aim of this study was to evaluate the influence of antibiotic treatment on outcome in the conservative management of patients with mild AD.

A retrospective audit of 311 patients (64% F, mean age 60 years) hospitalized for AD was carried out. All patients were initially treated conservatively with observation and restriction of oral intake. Patients receiving antibiotics (n=118) were compared with patients treated with observation and restriction of oral intake only (n=193). Mean follow-up time (FU) was 30 months.

Inflammation in patients treated with antibiotics was more pronounced (laboratory parameters (C-reactive protein, white blood cell count) were higher (p<0.01), fever was more common (p<0.01) and CT grading of inflammation was classified as severe in a higher proportion (p<0.01)) compared with patients treated without antibiotics. When initially treated with antibiotics, 3 patients (3%) failed to respond to treatment and had to undergo surgery. There were 7 (4%) failures in patients initially treated without antibiotics, and antibiotics were then added. During FU, 29% of patients treated with antibiotics had further events (recurrent AD and/or subsequent surgery) compared with 28% (NS) among those treated without antibiotics. In a multivariate analysis, the risk of a further event was not influenced by antibiotic treatment (OR 1.03, CI 95% 0.61-1.74).

Our results indicate that antibiotics are not mandatory in mild AD. Treatment without antibiotics appears to be safe and seems not to change the rate of further events. These results warrant further randomized prospective studies.