Members of different societies, including Paediatrics, Gastroenterology, Clinical Chemistry, Radiology and Pathology, involved in the treatment of children with inflammatory bowel disease (IBD) reached consensus during 12 meetings about definition, clinical and diagnostic work-up as well as initial treatment options in paediatric IBD. On the basis of history and physical examination a distinction is made between colitis-like or Crohn-like appearance. Further laboratory investigations are required in the presence of malnutrition, extraintestinal manifestations or growth retardation. Pathology plays an important part in the final diagnosis. Special attention is given to pubertal staging and height measurements as routine aspects of the treatment of children with IBD.