title: Therapeutic gastrointestinal endoscopy. Problems in proving efficacy.
authors.forename: P B
authors.initials: PB
authors.lastname: Cotton
mesh_terms: D000208:Acute Disease; D002761:Cholangitis / Q000601:surgery / Q000628:therapy*; D004322:Drainage / Q000379:methods*; D016099:Endoscopy, Gastrointestinal; D006801:Humans; D011897:Random Allocation; D015607:Stents