[1] HELIOS Albert Schweitzer Hosp Northeim, Dept Gastroenterol, Northeim, Germany
[2] HELIOS Med Ctr Siegburg, Siegburg, Germany
[3] HELIOS St Marienberg Hosp Helmstedt, Helmstedt, Germany
[4] Univ Munster, Inst Biostat & Clin Res, D-48149 Munster, Germany
[5] Zollernalb Med Ctr, Dept Gastroenterol, Bailingen, Germany
[6] Univ Med Ctr Gottingen, Dept Gastroenterol 2, Gottingen, Germany
[7] Univ Med Ctr Gottingen, Inst Pathol, Gottingen, Germany