Acute complicated diverticulitis (ACD) is a frequent surgical emergency that can be life-threatening. It encompasses various clinical entities, including colonic perforations, abscesses (Hinchey II), fistulas, and purulent or fecal peritonitis (Hinchey III/IV). Historically, the Hartmann procedure (HP) was established as the standard of care for diffuse peritonitis, particularly in frail patients. However, this intervention is associated with high rates of permanent stomas, long-term complications, and impaired quality of life. Over the past decade, several randomized controlled trials (RCTs) have compared HP with sigmoid resection and primary anastomosis (PA), sometimes combined with a diverting ileostomy. Results from these studies, notably the LADIES and DIVERTI trials, indicate that in hemodynamically stable and immunocompetent patients, PA is associated with superior functional outcomes, fewer late complications, and higher stoma reversal rates. Other minimally invasive approaches, such as laparoscopic peritoneal lavage for Hinchey III, have also been explored, showing promise in reducing stomas and reinterventions. However, their efficacy relies on stringent patient selection, and their use is not recommended by current guidelines (e.g., HAS 2017) due to higher reintervention rates. Recent epidemiological data suggest a trend toward reducing emergency surgical interventions in favor of more conservative strategies in selected cases, such as initial medical management followed by elective surgery. In this context of diversifying therapeutic options, choosing the optimal treatment requires a delicate balance between efficacy, morbidity, mortality, quality of life, and long-term preservation of intestinal function. Despite these advances, several questions remain, particularly regarding patient selection criteria and the real-world long-term impact of these interventions. A potentially underestimated factor is the role of the operator, as a significant portion of emergency cases (nights and weekends) are handled by surgeons in training.

Primary Objective: To provide a comprehensive overview of current management strategies for acute complicated diverticulitis by identifying preferred therapeutic modalities (conservative management, emergency surgery, delayed surgery) at the HUB (Hôpital Universitaire de Bruxelles).

Secondary Objectives: To evaluate the adherence of these therapeutic approaches to international guidelines. To identify clinical and context-specific predictive factors influencing the choice of therapeutic strategy.

Inclusion Criteria:

• Patients presenting with a first episode or recurrence of acute complicated diverticulitis.
• CT scan confirmation of a Hinchey stage ≥ Ib (including stages Ib, II, III, and IV) at admission.
• Initial management performed within the HUB (Hôpital Universitaire de Bruxelles) network.
• Hospital admission between January 1, 2015, and December 31, 2024.

Exclusion Criteria:

• Uncomplicated acute diverticulitis, defined by a CT scan Hinchey stage of 0 or Ia.
• Patients in whom the diagnosis of acute diverticulitis was ultimately ruled out during medical chart review.
• Patients whose initial management occurred at another hospital facility (outside the HUB network).
• Incomplete medical records preventing the reliable extraction of clinical or follow-up data.

Patients older than 18 years who were treated for acute complicated diverticulitis between January 1, 2015 and December 31, 2024 at Erasme Hospital and Institut Jules Bordet.

Individual participant data (IPD) will not be shared in order to protect patient confidentiality and comply with European data protection regulations (GDPR) and institutional privacy policies.