**Background:** Colonic diverticula and superficial neoplastic lesions (polyps and colorectal cancer) are common findings during screening colonoscopy. Whether a pathophysiological connection exists between these conditions beyond shared risk factors (e.g., age, diet, Western lifestyle) has been debated, with prior studies yielding conflicting results. This study aimed to evaluate the association between diverticulosis and colonic neoplastic lesions in asymptomatic patients undergoing screening colonoscopy.
**Methods:** This cross-sectional study included 1,501 asymptomatic patients who underwent screening colonoscopy between 2020 and 2021 at three Italian centers (University of L'Aquila/San Salvatore Hospital and G. Mazzini Hospital, Teramo). Inclusion criteria were first-time screening, positive fecal occult blood test, surveillance after polypectomy within 5 years, or first-degree family history of CRC. Exclusion criteria included previous colonic resection, inflammatory bowel disease, inadequate bowel preparation (Boston scale < 6 or < 2 in any segment), ischemic/infective colitis, or incomplete examination. All polypoid lesions were removed for histology; non-resectable lesions were biopsied. Data on lesion number, localization, morphology, size, and surface pattern were collected. Diverticulosis was defined as asymptomatic presence of diverticula. Statistical analysis used chi-square or Fisher's exact test, relative risk (RR) with 95% CI, and multivariate logistic regression with odds ratios (OR) adjusted for age, gender, family history of CRC, family history of diverticula, and presence of diverticula.
**Key Results:** Of 1,501 patients (mean age 63.3 years, SD ± 10.4; 50.63% female), 35.11% (527/1501) had diverticulosis, 47.04% (706/1501) had polyps, and 2.35% (34/1501) had CRC. Adenomas were found in 35.11% (507/1501), hyperplastic polyps in 15.93% (230/1501), and inflammatory polyps in 0.97% (14/1501). Patients were divided into four groups: Group A (diverticulosis only, n = 259, 17.26%), Group B (polyps/CRC only, n = 459, 30.58%), Group C (both, n = 268, 17.85%), and Group D (neither, n = 515, 34.31%). There was no statistically significant association between all polyp types/CRC and diverticula (RR 1.07, 95% CI 0.97–1.19, p = 0.18). However, a statistically significant association was found between adenomas or CRC alone and diverticula (RR 1.09, 95% CI 1.00–1.186, p = 0.045). On multivariate analysis, only age was significantly associated with adenoma/CRC development (OR 1.05 per year, 95% CI 1.03–1.07, p < 0.0001). Diverticulosis was not independently associated (OR 1.05, 95% CI 0.64–1.72, p = 0.834). The authors note a threefold increased risk in patients over 60 compared to younger patients (OR 3.06, 95% CI 1.88–4.93).
**Clinical Implications:** This study found a statistically significant unadjusted association between diverticulosis and colorectal adenomas/cancer, but this association was not independent of age on multivariate analysis. The findings suggest that the apparent link between diverticulosis and neoplastic lesions may be largely driven by shared risk factors, particularly advanced age. The authors emphasize that a cause-effect relationship cannot be established due to the cross-sectional design. They call for prospective studies comparing patients with and without diverticulosis to determine the incidence of adenoma and CRC, which could inform whether closer endoscopic surveillance is warranted for patients with diverticulosis. The study's limitations include self-reported indications for surveillance, a limited number of CRC cases, and the inherent inability of cross-sectional designs to establish causality.