Current and future trends in colorectal cancer screening.

Current modalities for colorectal cancer screening include fecal occult-blood testing, flexible sigmoidoscopy, colonoscopy, and double-contrast barium enema. Among these, colonoscopy is becoming the dominant modality, in light of its efficacy and continuing technical refinements. Emerging technologies, such as stool DNA tests and virtual colonoscopy, hold promise for the future but cannot be recommended for screening at present.