title: Questions concerning fecal porphyrins.
authors.forename: W E
authors.initials: WE
authors.lastname: Schreiber
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005243:Feces / Q000032:analysis*; D006801:Humans; D011166:Porphyrins / Q000032:analysis*
chemical_list: D011166:Porphyrins