Inflammatory Bowel Disease: Diagnosis and Evaluation

Abstract

The causes of ulcerative colitis (UC) and Crohn’s disease (CD) are unknown. Variations in diagnostic criteria, definitions of disease, and biases resulting from surveys done in tertiary care specialty centers, make universal conclusions difficult. However, some general statements can be made using such data that relate to disease prevalence and associated risk factors (Table 39.1). Inflammatory bowel disease (IBD) is found most frequently in the more temperate climates of North America and Europe. Studies from those regions show prevalence rates much higher than those in Asia, South America, or Africa. It is generally recognized that both CD and UC have been increasing in incidence to a remarkable degree over the past 20–30 years with twofold to tenfold increases depending on population and region studied.