Management of acute uncomplicated diverticulitis without antibiotics: a systematic review, meta-analysis, and meta-regression of predictors of treatment failure

Background Diverticulitis is a common complication of diverticular disease of the colon. While complicated diverticulitis often warrants intervention, acute uncomplicated diverticulitis (AUD) is usually managed conservatively. The aim of the present review was to evaluate the efficacy and safety of conservative treatment of AUD without antibiotics compared to standard antibiotic treatment. Methods A systematic literature review in compliance with PRISMA guidelines was conducted. Electronic databases including PubMed/Medline, Scopus, Embase and Cochrane central register of controlled trials were searched. Studies that assessed efficacy and safety of treatment of AUD without antibiotics were included. Outcome parameters were rates of treatment failure, recurrence of diverticulitis, complications and mortality, readmission to hospital, and need for surgery. Results Nine studies including 2565 patients were included to the review. Of these patients, 65.1% were treated conservatively without antibiotics. Treatment failure was observed in 5.1% of patients not-given-antibiotic treatment versus 3.4% of those given antibiotic treatment. Recurrent diverticulitis occurred in 9.3% of patients in the non-antibiotic group versus 12.1% of patients in the antibiotic group. On meta-analysis of the studies, there were no significant differences between non-antibiotic and antibiotic treatment groups regarding rates of treatment failure (OR = 1.5, p = 0.06), recurrence of diverticulitis (OR = 0.81, p = 0.2), complications (OR = 0.56, p = 0.25), readmission rates (OR = 0.97, p = 0.91), need for surgery (OR = 0.59, p = 0.28), and mortality (OR = 0.64, p = 0.47). The only variable that was significantly associated with treatment failure in the non-antibiotic treatment group was associated comorbidities (standard error (SE) = -0.07, 95% CI -0.117 -0.032; p < 0.001). Conclusions Treatment of AUD without antibiotics is feasible, safe, and effective. Adding broad-spectrum antibiotics to the treatment regimen did not serve to decrease treatment failure, recurrence, complications, hospital readmissions, and need for surgery significantly compared to non-antibiotic treatment.