Background: With more than 5,000 colonoscopies provided to patients from almost 200 countries annually, the data in Bumrungrad Colonoscopy Registry (BCR) is beneficial for comparative analysis across ethnic groups.

Objective: To describe the results of colonoscopy findings of colonic symptom-free patients from various ethnic groups.

Materials and Methods: Using the BCR dataset, a random sample of subjects underwent colonoscopy between 2007 and 2011 were reviewed. Patients aged at least 50 years without colonic symptoms or history of colonic diseases were included.

Results: Of the 26,508 subjects, 2,651 were randomly selected and 1,300 subjects met the inclusion criteria. Abnormal findings were identified in 878 cases (67.54%), of which 452 cases were found to have 940 polyps. Seven cancer lesions were found in six cases. Of the 452 patients, half had only one polyp (53.76%) and were Asian (54.65%), followed by Caucasian (26.99%), and Middle Eastern (15.71%). Ethnicity-specific polyp incidences were 36.26%, 38.05%, and 27.24%, respectively. Polyps of Caucasian subjects tended to be smaller (4.52 mm) and locate on the left side of colon (65.63%) more than that of the other ethnicities (44.44% to 60.53%). Most of the polyps (84.04%) were small (≤5 mm). Hyperplastic polyp, tubular adenoma (TA), and tubulovillous adenoma (TVA) were identified in 43.19%, 53.83%, and 2.34%, respectively. Pre-malignant (TA+TVA) polyps were found in 56.08%, 50.19%, and 64.23% of the polyps of Asian, Caucasian, and Middle Eastern patients, respectively. Interestingly, pre-malignant lesions were found in 52.91% of the small polyps.

Conclusion: Number, size, distribution, and pathological type of colonic polyps vary across ethnic groups. As more than half of small polyps were TA, polyps of all sizes should be removed when feasible.

Keywords: Colonoscopy, Polyps, Colon cancer, Epidemiology, Ethnicity

Received 8 May 2017 | Revised 30 Oct 2018 | Accepted 13 Nov 2018