1. Neurogastroenterology Unit Manchester University NHS Foundation Trust Wythenshawe Hospital Manchester UK
2. Division of Diabetes, Endocrinology and Gastroenterology University of Manchester Manchester UK
3. Division of Gastroenterology, Department of Medicine Beth Israel Deaconess Medical Center Boston Massachusetts USA
4. The Henry D. Janowitz Division of Gastroenterology The Icahn School of Medicine at Mount Sinai New York New York USA