Randomized clinical trial of observational versus antibiotic treatment for a first episode of CT-proven uncomplicated acute diverticulitis

Br J Surg. 2017 Jan;104(1):52-61. doi: 10.1002/bjs.10309. Epub 2016 Sep 30.


Background: Antibiotics are advised in most guidelines on acute diverticulitis, despite a lack of evidence to support their routine use. This trial compared the effectiveness of a strategy with or without antibiotics for a first episode of uncomplicated acute diverticulitis.

Methods: Patients with CT-proven, primary, left-sided, uncomplicated, acute diverticulitis were included at 22 clinical sites in the Netherlands, and assigned randomly to an observational or antibiotic treatment strategy. The primary endpoint was time to recovery during 6 months of follow-up. Main secondary endpoints were readmission rate, complicated, ongoing and recurrent diverticulitis, sigmoid resection and mortality. Intention-to-treat and per-protocol analyses were done.

Results: A total of 528 patients were included. Median time to recovery was 14 (i.q.r. 6-35) days for the observational and 12 (7-30) days for the antibiotic treatment strategy, with a hazard ratio for recovery of 0·91 (lower limit of 1-sided 95 per cent c.i. 0·78; P = 0·151). No significant differences between the observation and antibiotic treatment groups were found for secondary endpoints: complicated diverticulitis (3·8 versus 2·6 per cent respectively; P = 0·377), ongoing diverticulitis (7·3 versus 4·1 per cent; P = 0·183), recurrent diverticulitis (3·4 versus 3·0 per cent; P = 0·494), sigmoid resection (3·8 versus 2·3 per cent; P = 0·323), readmission (17·6 versus 12·0 per cent; P = 0·148), adverse events (48·5 versus 54·5 per cent; P = 0·221) and mortality (1·1 versus 0·4 per cent; P = 0·432). Hospital stay was significantly shorter in the observation group (2 versus 3 days; P = 0·006). Per-protocol analyses were concordant with the intention-to-treat analyses.

Conclusion: Observational treatment without antibiotics did not prolong recovery and can be considered appropriate in patients with uncomplicated diverticulitis. Registration number: NCT01111253 (http://www.clinicaltrials.gov).

Publication types

  • Multicenter Study
  • Pragmatic Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Acute Disease
  • Amoxicillin-Potassium Clavulanate Combination / therapeutic use
  • Anti-Bacterial Agents / therapeutic use*
  • Colon, Sigmoid / surgery
  • Diverticulitis, Colonic / diagnostic imaging
  • Diverticulitis, Colonic / epidemiology
  • Diverticulitis, Colonic / therapy*
  • Female
  • Humans
  • Length of Stay / statistics & numerical data
  • Male
  • Middle Aged
  • Netherlands / epidemiology
  • Patient Readmission / statistics & numerical data
  • Recovery of Function
  • Tomography, X-Ray Computed
  • Visual Analog Scale
  • Watchful Waiting*


  • Anti-Bacterial Agents
  • Amoxicillin-Potassium Clavulanate Combination

Associated data

  • ClinicalTrials.gov/NCT01111253