[1] Univ Amsterdam, Amsterdam UMC, Emma Childrens Hosp, Pediat Gastroenterol, Room C2-312,POB 22700, NL-1100 DD Amsterdam, Netherlands
[2] Dutch Child & Hosp Fdn, Utrecht, Netherlands
[3] Bernhoven, Dept Pediat, Uden, Netherlands
[4] Ommelander Hosp Groningen, Dept Pediat, Groningen, Netherlands
[5] Rijnstate, Dept Pediat, Arnhem, Netherlands
[6] Dutch Patient Federat, Utrecht, Netherlands