The prevalence rate and anatomic location of colorectal adenoma and cancer detected by colonoscopy in average-risk individuals aged 40-80 years.

Background: The role of screening colonoscopy for colorectal (CR) neoplasia in average-risk population, remains to be determined.

Objectives: To evaluate the prevalence and anatomic location of CR adenoma and carcinoma and the morbidity of colonoscopy in individuals at average risk for CR cancer (CRC).

Methods: A retrospective prevalence study of subjects aged 40-80 yr, with no cancer-related symptoms, personal or family history of CR neoplasia, who underwent a colonoscopy.