Patients' Experiences of Telephone-Based and Web-Based Cognitive Behavioral Therapy for Irritable Bowel Syndrome: Longitudinal Qualitative Study by Hughes, Stephanie, Sibelli, Alice, Everitt, Hazel A, Moss-Morris, Rona, Chalder, Trudie, Harvey, J Matthew, Vas Falcao, Andrea, Landau, Sabine, O'Reilly, Gilly, Windgassen, Sula, Holland, Rachel, Little, Paul, McCrone, Paul, Goldsmith, Kimberley, Coleman, Nicholas, Logan, Robert, Bishop, Felicity L