title: Flexible sigmoidoscopy screening: is once enough?
authors.affiliation: National Cancer Institute, Bethesda, MD 20892, USA. Electronic address: pp4f@nih.gov.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Pinsky
mesh_terms: D015179:Colorectal Neoplasms; D006801:Humans; D008403:Mass Screening; D009780:Occult Blood; D012812:Sigmoidoscopy