Colorectal cancer is the second leading cause of death from cancer in the U.S., behind lung cancer. Numerous medical societies recommend routine screening for colorectal cancer with flexible sigmoidoscopy for people 50 and over. But who will perform the procedure, and who will pay for it? The case of flexible sigmoidoscopy illustrates the economic and practical issues of introducing a screening procedure into primary care practice. This Issue Brief investigates the role of primary care physicians in providing this service as part of routine care, and identifies attitudinal and financial barriers to overcome.