title: Reply.
authors.affiliation: Gastroenterology Unit, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Edward
authors.initials: E
authors.lastname: Shelton
authors.affiliation: Gastroenterology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Ashwin N
authors.initials: AN
authors.lastname: Ananthakrishnan