[1] Univ Zurich Hosp, Div Gastroenterol & Hepatol, CH-8091 Zurich, Switzerland
[2] Univ Zurich Hosp, Dept Dermatol, CH-8091 Zurich, Switzerland
[3] Stadtspital Triemli, Div Gastroenterol & Hepatol, Zurich, Switzerland
[4] Univ Zurich Hosp, Zurich Ctr Integrat Human Physiol, CH-8091 Zurich, Switzerland
[5] Seespital Horgen, Dept Internal Med, Horgen, Switzerland
[6] Robert Bosch Hosp Stuttgart, Div Gastroenterol & Hepatol, Stuttgart, Germany