Epidemiology of pediatric inflammatory bowel disease

Inflammatory bowel disease is a complex disease with an unknown etiology. Strong environmental influences have been implicated as the reason for the observed exponential increased incidence of IBD over the last five decades since the genetic determinants do not change within this short period of time. However, most of the environmental risks and associations are reported from retrospective data collection or questionnaire-based adult studies, and have not been systematically studied in a prospective and longitudinal format in a large population based cohort. With the association and identification of potential genetic loci for IBD, complex interaction between the environmental and genetic influences may well be within our reach. Continued assessment of pediatric epidemiology is necessary as the clinical presentation, progression of disease, risk factors for surgery and malignancy may drastically be altered in the next decade. It should be obvious to most people that if new discoveries are to be attained concerning the cause of IBD, the barriers to relaxing the assumptions of gene-environment interactions need immediate attention. The first design issue in studying a complex disorder like IBD is to identify and characterize the right population. Investigators should recognize this problem rather than simply work with convenient samples. For a variety of reasons, children with newly diagnosed IBD (incident cases) are ideally suited to carry out such investigations. It is imperative that pediatric focused, multicenter consortia efforts be established and tasked to develop well designed benchmarks for studying influences of environmental factors along with genetic determinants on early onset IBD.