[1] Sez Gastroenterol & Epatol, Lab Motilita Intestinale, I-06100 Perugia, Italy
[2] Univ Perugia, Sch Med, Gerontol & Geriatr Sect, I-06100 Perugia, Italy
[3] Univ Perugia, Sch Med, Dept Clin & Expt Med, Internal Med Angiol & Atherosclerois Dis Sect, I-06100 Perugia, Italy
[4] Univ Perugia, Sch Med, Dept Internal Med Endocrine & Metab Sci, I-06100 Perugia, Italy
[5] Univ Turin, Sch Med, Dept Clin Pathophysiol, I-10124 Turin, Italy
[6] Univ Verona, Sch Med, Valeggio Mincio Hosp, Div Gastroenterol Rehabil, I-37100 Verona, Italy