[1] Univ Bern, Bern Univ Hosp, Inselspital,Dept Paediat, Div Pediat Gastroenterol Hepatol & Nutr, Freiburgstr 15, CH-3010 Bern, Switzerland
[2] Ctr Hosp Univ Vaudois CHUV, Div Pediat Gastroenterol, Lausanne, Switzerland
[3] Univ Lausanne, Lausanne, Switzerland
[4] Childrens Hosp LUKS, Div Pediat Gastroenterol Hepatol & Nutr, Luzern, Switzerland
[5] Univ Childrens Hosp Zurich, Div Pediat Gastroenterol Hepatol & Nutr, Zurich, Switzerland
[6] Ctr Hosp Univ Vaudois CHUV, Div Gastroenterol & Hepatol, Lausanne, Switzerland
[7] Univ Lausanne, Ctr Primary Care & Publ Hlth, Dept Epidemiol & Hlth Syst, Lausanne, Switzerland