Crohn's Disease in the UK

It is estimated that up to one million Americans suffer from Crohn’s disease or ulcerative colitis (collectively known as inflammatory bowel diseases, or IBD). The search for risk factors in IBD has been frustrating, and the difficulty in diagnosing these diseases has been a further hindrance. However, epidemiologists have gathered enough information to know a good deal about the distribution of IBD in the United States and Western Europe. Current evidence suggests that both genetic and environmental factors contribute to these diseases.

GENETICS
Though researchers have not yet identified the genes responsible for IBD, they agree that these illnesses have a strong genetic component. If a person has a relative with the disease, his/her risk is estimated to be at least 10 times that of the general population–30 times greater if the relative is a sibling. New technologies, including a genome-wide search, are helping researchers to close in on the genes that predispose people to IBD.

RACE AND ETHNICITY

American Jews of European descent are four to five times more likely to develop IBD than the general population.

IBD has long been considered a predominantly white disease. The prevalence rate among whites is 149 per 100,000. Among African Americans, however, there has been a steady increase in reported cases of both Crohn’s disease and ulcerative colitis. An HMO with two million members reported hospitalization rates per 100,000 by race, over a six-year period, as:
10.2 – Whites
10.2 – African Americans

According to this study, prevalence rates among Hispanics and Asians were lower than those for whites and African Americans.

GENDER
The incidence of IBD does not appear to be significantly different between men and women.

AGE

IBD can begin at any age, but adolescents and young adults between the ages of 15 and 35 are most susceptible.

Ten percent, or an estimated 100,000, of those afflicted are youngsters under the age of 18.

After age 50, there is a smaller second wave of new cases.