Further information consolidating the roles of dietary fat and fiber and physical inactivity in colorectal carcinogenesis has been published in the year under review. A large cohort study identified animal fat as the most important dietary risk factor, and a meta-analysis of fiber supported the role particularly of vegetable fiber in protection. An important population-based study in Scandinavia identified age at onset of ulcerative colitis as a factor independent of length of follow-up; risk at 35 years after onset was 40% for those with early-stage onset. An update at the St. Mark's Hospital, London, surveillance experience offers measured support for endoscopic screening for dysplasia and curable cancer. A unique paper from Japan defines a relative risk of cancer after polypectomy of 2.3. A case-control study of occult blood screening showed that the sensitivity of guaiac testing for fecal occult blood (Hemoccult, Smith Kline Diagnostics, CA) for asymptomatic colorectal cancer is just under 50%. Cost-benefit modeling suggests that annual occult blood testing and 3- to 5-yearly flexible sigmoidoscopy are optimal.