Outpatient management of uncomplicated acute diverticulitis: experience after implementing a protocol with selective antibiotic omission

Routine antibiotic use in uncomplicated acute diverticulitis (UAD) lacks scientific support in selected patients. We evaluated the safety and clinical impact of implementing an outpatient protocol with selective antibiotic omission.

Single-centre observational study (2010-2025) including 658 patients with grade 0 UAD (World Society of Emergency Surgery classification) confirmed by computed tomography. Period A (retrospective cohort, pre-protocol, n = 286, 2010-2020) was compared with Period B (prospective cohort, post-protocol, n = 372, 2021-2025). In Period B, antibiotics were withheld in the absence of fever ≥37,5°C, C-reactive protein>50mg/L, leukocytosis>11×10⁹/L, and severe pain.

emergency revisit and unplanned hospitalisation at 30 days.

In Period A, 99.3% received antibiotics, with revisit 8.0% (23/286) and hospitalisation 2.4% (7/286). In Period B, 22.3% (83/372) were managed without antibiotics, a 21.6% absolute reduction (p < 0.001). In the antibiotic-free group, revisit was 3.6% (3/83) and hospitalisation 1.2% (1/83). No comparison of revisit or hospitalisation rates reached statistical significance (p > 0.05).

A clinical and laboratory-based protocol significantly could reduce antibiotic use in grade 0 UAD without increasing revisit or hospitalisation rates, supporting rational antibiotic use and antimicrobial stewardship strategies. .