Problems in diagnosis of IBD in children.

Children and adolescents with inflammatory bowel disease (IBD) present unique challenges to physicians and all health-care providers. The most important aspect is that children are not small adults. They are characterized by a highly dynamic state of growth and physical change as well as a constant alteration in psychological status. It will not be difficult to recognize IBD, even in children, when it presents with classical symptoms such as bloody diarrhoea, abdominal pain and weight loss. However, some children will present with abdominal pain and depression. Not infrequently these children are diagnosed as being depressed and are seen and treated by psychologists and psychiatrists for different periods of time. In addition, several children will be initially diagnosed as having a bacterial gastroenteritis with a proven positive faecal culture. It seems to be the triggering event in these children, and if adequate therapy fails, colonoscopy is indicated. Recently, Beattie et al. showed that in children seen for chronic abdominal pain simple routine blood tests including full blood count and erythrocyte sedimentation rate are almost always abnormal in children with IBD. But most importantly, growth retardation is common in children with IBD and is more often found in Crohn's disease (CD) than in ulcerative colitis (UC). Faltering growth is a sign of a catabolic situation. Therefore, it is essential to follow the growth of children at the beginning and during treatment of IBD. Growth retardation can be the first symptom of IBD and is often already present before other symptoms of IBD become apparent. Rarely, extra-intestinal manifestations, particularly arthritis, can be the first and sometimes only initial symptom for months to years in children with IBD. About 2% of all patients with IBD present before the age of 10 years, but 30% present between the age of 10 and 19 years. A significant proportion of young patients with IBD will develop the disease just prior to or during puberty. Adolescent growth is characterized by rapid accumulation of lean body mass and any inflammatory disease occurring at this time is likely to have a major impact on nutritional status and growth. This rapid growth requires an appropriate increase in nutritional substrates and failure to achieve catch-up growth may ultimately lead to poor cumulative growth over time. Most of the growth retardation is seen in children with CD, approximately 30%. However, also in UC 15% will show a reduction in growth. The higher percentage in CD could be due to the disease itself or to the relative subtlety of the intestinal manifestations of CD, mainly abdominal pain and general malaise. Not only growth, but also delayed puberty, is a sign of an ongoing disease that most likely needs more intensive treatment. It has been shown that the severity of disease activity plays a more important role in the occurrence of growth retardation than steroid treatment. Therefore in paediatrics it is important to state that growth retardation during medical treatment equals undertreatment. In contrast to adults, the potential benefit of nutritional therapy should be seriously considered in addition to aggressive medical therapy including steroids and other immunosuppressive agents such as azathioprine. The most convincing evidence that malnutrition is primarily responsible for growth failure is based on depletion studies. The malnutrition itself is caused by ongoing inflammation and loss of appetite. Recommendations for nutritional therapy include an increase in energy and protein intake to 150% of recommended daily allowances for height and age. Some studies have shown the benefit of nocturnal nasogastric infusion as supplements of daily intake. Importantly, nutritional support has been shown to be as effective as steroids in achieving remission of disease in children. Furthermore, no significant differences have been shown in studies using elemental versus polymeric diets.