1. Department of Hepato-Gastro-Enterology, University Hospital Center, 87042 Limoges, France
2. Medical Clinic for Gastroenterology at the Hospital Duesseldorf, 40225 Duesseldorf, Germany
3. Erbe Elektromedizin GmbH, 72072 Tuebingen, Germany
4. Department of Experimental Medicine, University Hospital Tuebingen, 72076 Tuebingen, Germany
5. Endoscopy Unit, Humanitas Clinical and Research Center IRCCS, 20089 Milan, Italy
6. Department of Biomedical Science, Humanitas University, 20072 Milan, Italy