The role of screening colonoscopy after appendicitis in patients over 40 years of age.

Background: There is some evidence of the association between acute appendicitis and colorectal neoplasm in patients over the age of 40 years. Despite this, few centres routinely evaluate the colon endoscopically following an episode of appendicitis in these patients. Our aim was to investigate the incidence of colorectal neoplasm in patients aged 40 years and over who underwent screening colonoscopy following acute appendicitis.

Methods: Retrospective cohort study of patients aged 40 years and over who were diagnosed with acute appendicitis via imaging or histology between January 2015 and May 2022. Findings on subsequent screening colonoscopy were evaluated and classified according to adenomatous and non-adenomatous lesions.

Results: A total of 176 patients met inclusion criteria, with a median age of 54 years (range 40-92) and female to male ratio of 1:1.3. One hundred patients (56%) had a colonoscopy following their admission, at a mean duration of 3.5 months post discharge. 15% of patients had an adenomatous polyp detected (10 adenomas, 4 advanced adenomas, and 1 sessile serrated adenoma), and 9% had a non-adenomatous lesion detected (8 hyperplastic polyps and 1 lipoma).

Conclusion: Adenoma detection rate in patients aged 40 years and over undergoing colonoscopy after acute appendicitis was 15% in our cohort. This high adenoma detection rate supports the view of appendicitis as an indication for screening faecal immunochemical testing or colonoscopy in patients above 40 years.