Controversy remains over the role of risk factors in developing colorectal polyps. The aim of this study was to investigate the relationship of colorectal polyps with risk factors including obesity, age, alcohol, and smoking. We retrospectively assessed colorectal polyps through medical records and patient interviews of 1080 patients who underwent colonoscopy regardless of symptoms. The degree of obesity was determined by body mass index (BMI), and colorectal polyps were divided into hyperplastic and adenomatous polyps. The prevalence of colorectal polyps was 45.3% (489 patients). Of these, the prevalences of hyperplastic polyps and adenomatous polyps were 23.3% and 26.7%, respectively. The most common number, size, and location of colorectal polyps were one (63.8%), 5.0∼9.0 mm (50.1%), and rectosigmoid colon (35.7%), respectively. Age, amount of alcohol, and smoking were significantly higher in the group with polyps than in that without polyps (54.9±11.3 vs. 50.0±13.1 years, 75.8 vs. 39.3 g/week, and 9.3±12.6 vs. 4.6±9.1 pack years, respectively, p=0.001). There were no significant differences in BMI between the groups with (23.2 kg/m 2 ) or without (23.1 kg/m 2 ) polyps. Also, there was no significant relationship between BMI and the size, number, or location of colorectal polyps. Age, alcohol, and smoking were associated with colorectal polyps by one-way ANOVA test but not by multivariate logistic regression analysis. Additionally, BMI had no relationship with the size, number, or location of colorectal polyps. In conclusion, age, alcohol drinking, and smoking may be associated with colorectal polyps, but obesity as assessed by BMI was not.
