[1] Erasmus MC Sophia Childrens Hosp, Dept Paediat Gastroenterol, NL-3015 GJ Rotterdam, Netherlands
[2] St Marien Hosp, Dept Paediat, Bonn, Germany
[3] Royal Hosp Children, Dept Paediat Gastroenterol, Bristol, Avon, England
[4] Hvidovre Univ Hosp, Dept Paediat, Copenhagen, Denmark
[5] Semmelweis Univ, Dept Paediat 1, Budapest, Hungary
[6] Hosp Sao Joao, Dept Paediat, Oporto, Portugal