1 Division of Gastroenterology, Medical Department II, University of Leipr, Leipzig, Germany.
2 Division of Gastroenterology, Gastrointestinal Oncology and Interventional Endoscopy, Sana Clinic Offenbach, Offenbach, Germany; Clinic for Gastroenterology, Gastrointestinal Oncology and Endocrinology, University of Göttingen, Göttingen, Germany.