[1] St Vincents Hosp Sydney, Dept Gastroenterol & Hepatol, Darlinghurst, Australia
[2] Univ New South Wales, Sch Clin Med, St Vincents Healthcare Campus, Sydney, Australia
[3] Univ Coll London Hosp, Ctr Med Imaging, London, England
[4] Univ Notre Dame, Sch Med, Dept Surg, Sydney, Australia
[5] Univ Coll London Hosp, GI Physiol Unit, London, England
[6] St Vincents Hosp Sydney, Ctr Swallowing & Oesophageal Disorders, 390 Victoria St, Darlinghurst, NSW 2010, Australia