Medical treatment of uncomplicated acute diverticulitis is not standardized and there is an enormous diversity in clinical practice. The investigators' aim was to demonstrate that uncomplicated diverticulitis can be managed with oral amoxicillin plus clavulanic acid with a short hospital admission.

A prospective randomized trial was established to compare patients with uncomplicated diverticulitis who received oral antibiotic after a short course of intravenous antibiotic, with those who received intravenous antibiotic for a longer period. We included 50 patients, 25 in each group. Patients in group 1 begun oral antibiotic as soon as they improved and were discharged the day after. Patients in group 2 received intravenous antibiotic for 7 days. Both groups received oral antibiotic at discharge. The endpoint of the study was "failure of treatment" which was defined as the impossibility of discharging on the expected day, emergency admission or hospital readmission.

Inclusion Criteria:

• clinical diagnosis of uncomplicated acute diverticulitis confirmed by a computed tomography (CT) scan within 24-48 hours

Exclusion Criteria (prerandomization):

• immunocompromised patients
• pregnant women
• clinical suspicion or CT confirmation of complicated acute diverticulitis
• Karnofsky performance score less than 50%
• allergy to penicillin

Exclusion Criteria (postrandomization):

• withdrawal of the trial
• CT confirmation of complicated acute diverticulitis
• CT not conforming to acute diverticulitis
• CT performed 72 hours after the admission
• adverse reaction to the antibiotic
• bacteriemia