Els van de Vijver

10 Inflammatory Bowel Disease Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with two distinct phenotypes: Crohn’s disease (CD) and ulcerative colitis (UC). Approximately 10% of all patients with IBD manifestations in the colon have overlapping features of both phenotypes and are categorized as ‘IBD unclassified’ (IBDU).(1) CD has a classic triad of presenting symptoms: abdominal pain, weight loss and diarrhoea. In contrast, weight loss is relatively rare as presenting symptom in patients with UC, in which rectal bleeding tends to be more prominent at the time of diagnosis. Clinical presentation of either of the two types of IBD varies according to the location, severity and chronicity of inflammation.(2) About 10% of all new patients with IBD are younger than 19 years of age at the time of diagnosis.(3) Compared to adults, children are more likely to present with extensive disease and to be at greater risk of complications.(2) Strategies for diagnosing IBD, alleviating symptoms and improving well-being have been subjects of intensive research. Nevertheless, conclusive answers have yet to be provided regarding important research questions concerning the management of paediatric IBD (see Table 1 for current knowledge gaps). Chapter 1