1. Interventional and Experimental Endoscopy (InExEn), Internal Medicine II, University Hospital Würzburg, Würzburg, Germany
2. Department of Internal Medicine and Gastroenterology, Katharinenhospital, Stuttgart, Germany
3. Department for Interdisciplinary Endoscopy; Department of Internal Medicine I; and Department of Computational Neuroscience, University Hospital Hamburg - Eppendorf, Hamburg, Germany