[1] Queen Mary Univ London, Barts & London Sch Med & Dent, Acad Surg Unit, London, England
[2] Queen Mary Univ London, Barts & London Sch Med & Dent, Neurogastroenterol Grp, London, England
[3] Univ Med Ctr Utrecht, Wilhelmina Childrens Hosp, Dept Pediat, Utrecht, Netherlands
[4] Emma Childrens Hosp, Acad Med Ctr, Dept Pediat Gastroenterol & Nutr, Amsterdam, Netherlands