Background: Acute diverticulitis is a common surgical presentation characterised by inflammation of colonic diverticula, which can present with abdominal pain, fever, and raised inflammatory markers. Colorectal cancer (CRC) and diverticulitis share similar risk factors and symptoms, creating diagnostic challenges. This audit aimed to determine the incidence of CRC in patients presenting with acute diverticulitis over a 5-year period, alongside assessing final outcomes and adherence to diagnostic and follow-up guidelines.

Methods: A retrospective study was conducted across a large NHS Trust, including patients with a discharge diagnosis of diverticulitis over a five-year period from 2019 to 2024. Clinical data, imaging, and follow-up outcomes were reviewed using electronic records. The primary outcome was the incidence of CRC and secondary outcomes included follow-up endoscopy rates and final patient outcomes.

Results: A total of 415 patients were included in this audit. CRC was diagnosed in 5 patients (1.2%), all of whom had complicated diverticulitis. CT imaging was performed in 98.5% of patients, confirming its role as the primary diagnostic tool. While 57.1% of patients had follow-up endoscopy booked, only 50.8% underwent endoscopic evaluation. Surgical intervention was required in 15.4% of cases, with Hartmann’s procedure being the most common operation. Mortality rate was 8.9%, primarily in older patients with comorbidities.

Conclusions: The incidence of CRC in this cohort aligns with published data. There was poor correlation between current guidelines and planned endoscopic assessment post discharge which requires re-evaluation of current practice.