Inflammatory Bowel Diseases

The term inflammatory bowel disease (IBD) refers to a group of chronic inflammatory disorders of unknown cause involving the gastrointestinal tract. Although chronic IBD is usually divided into two groups, ie, ulcerative colitis and Crohn disease, it is recognized that approximately 10% to 15% of cases cannot be classified as either of these disorders, and such cases are termed "indeterminant colitis." The incidence and prevalence of these diseases vary considerably in different countries. For instance, the annual incidence of ulcerative colitis ranges from 3 to 15 per 100 000 with a prevalence of 70 to 150 per 100 000 in different countries. The annual incidence of Crohn disease ranges from 0.5 to 6 per 100 000 with prevalence of 20 to 75 per 100 000. If one were to extrapolate from these numbers it could be estimated that there are 375 000 cases of ulcerative colitis and 200 000 cases