title: Reply to Petersen.
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Kavel H
authors.initials: KH
authors.lastname: Visrodia
authors.forename: Cori L
authors.initials: CL
authors.lastname: Ofstead
authors.forename: Hannah L
authors.initials: HL
authors.lastname: Yellin
authors.forename: Harry P
authors.initials: HP
authors.lastname: Wetzler
authors.forename: Pritish K
authors.initials: PK
authors.lastname: Tosh
authors.forename: Todd H
authors.initials: TH
authors.lastname: Baron
mesh_terms: D020776:Endoscopes, Gastrointestinal / Q000592:standards*; D004866:Equipment Contamination; D006801:Humans