Corrigendum: Development of the NIH Patient‐Reported Outcomes Measurement Information System (PROMIS) Gastrointestinal Symptom Scales. (April 2015) - Spiegel, Brennan M R; Hays, Ron D; Bolus, Roger; Melmed, Gil Y; Chang, Lin; Whitman, Cynthia; Khanna, Puja P; Paz, Sylvia H; Hays, Tonya; Reise, Steve; Khanna, Dinesh