title: Occult blood screening. Obstacles to effectiveness.
authors.affiliation: Division of Gastroenterology, Mayo Clinic, Rochester, MN 55905.
authors.forename: D A
authors.initials: DA
authors.lastname: Ahlquist
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000097:blood / Q000517:prevention & control*; D006801:Humans; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009780:Occult Blood; D012680:Sensitivity and Specificity