[1] Univ Hosp Ctr, Dept Hepatogastroenterol, F-87042 Limoges, France
[2] Hosp Duesseldorf, Med Clin Gastroenterol, D-40225 Dusseldorf, Germany
[3] Erbe Elektromed GmbH, D-72072 Tubingen, Germany
[4] Univ Hosp Tuebingen, Dept Expt Med, D-72076 Tubingen, Germany
[5] Humanitas Clin & Res Ctr IRCCS, Endoscopy Unit, I-20089 Milan, Italy
[6] Humanitas Univ, Dept Biomed Sci, I-20072 Milan, Italy