[1] Univ Cologne, Univ Childrens Hosp, Dept Paediat, D-50937 Cologne, Germany
[2] Med Univ Graz, Dept Paediat, Graz, Austria
[3] Univ Antwerp Hosp, Dept Paediat Gastroenterol, Antwerp, Belgium
[4] Univ Med Ctr Groningen, Dept Paediat Gastroenterol, Groningen, Netherlands
[5] Univ Hosp Cologne, Inst Med Stat & Bioinformat, Cologne, Germany
[6] Ctr Hosp S Joao, Dept Paediat, Unit Paediat Gastroenterol, Porto, Portugal
[7] Sheffield Childrens Hosp, Ctr Paediat Gastroenterol, Sheffield, S Yorkshire, England
[8] Alder Hey Childrens Hosp, Dept Paediat Gastroenterol Hepatol & Nutr, Liverpool, Merseyside, England