Is Barium Enema an Adequate Diagnostic Test for Patients With Positive FOBT?

The research protocol aim is to compare diagnostic tools for the proper evaluation of patient with fecal occult blood test positive (FOBT +), a routine screening test for colorecatl carcinoma. The purpose of this study is to determine if Double Contrast Barium Enema (DCBE), a specialized radiographic exam of the colon, is a reasonable alternative for the evaluation of patients with positive fecal occult blood as compared to colonoscopy, which is considered the best evaluation method. Colonoscopy involves the direct visualization of the colon using a flexible instrument. This permits the removal of polyps and to obtain biopsies. It involves additional risks, discomfort and costs. In fact the DCBE is the experimental procedure in this protocol. Additional aims of this study are: to determine the localization, number, size and pathologic characteristics, if applicable, of findings in colonoscopy and/or DCBE and to determine the patient preference between both studies. This study is limited to those patients 50 years or older who are at average risk for colon cancer and who had a positive fecal occult blood screening test.