1. National Bowel Research Centre & GI Physiology Unit; Queen Mary University of London; London UK
2. Department of Gastroenterology and Hepatology; University Hospital Zürich; Zürich Switzerland
3. Division of Gastroenterology & Hepatology; Department of Internal Medicine; Medical College of Georgia; Augusta University; Augusta GA USA
4. Abdominal Center: Gastroenterology; St. Claraspital; Basel Switzerland