Racial differences in epidemiology of irritable bowel syndrome alone, un-investigated dyspepsia alone, and "overlap syndrome" among african americans compared to Caucasians: a population-based study.

There is A paucity of data on racial differences in epidemiology of irritable bowel syndrome (IBS) alone and un-investigated dyspepsia (UD) alone compared to "overlap syndrome" (OS). We conducted a random survey (n = 990). Subjects completed a questionnaire which included Rome II criteria for IBS and functional dyspepsia (FD). Among African Americans, the prevalence of IBS alone, UD alone, and OS was 0.6%, 17%, and 7.3%, respectively. It was 0%, 13%, and 13% among Caucasian Americans. All but four patients with IBS had UD. Among patients with UD, OS was seen in 30% of African Americans, compared to 50% among Caucasian Americans. Among African Americans, UD patients were younger compared to OS patients. African Americans with UD were more likely than OS patients to have children. Marital status, education, and household income were not a factor among Caucasians. African Americans patients below poverty level were more likely to have UD than OS (22% vs 10%). Considering patients with UD alone, race, age, sex, marital status, number of children, education, and income level were not different between African Americans and Caucasians. Compared to African Americans, Caucasians with OS were likely to be married and live in an urban area. There was a higher prevalence of OS among Caucasians with lower education. OS is 2.5 times more likely to occur among Caucasians compared to African Americans. We conclude that OS is more common among Caucasians than African Americans. IBS and OS are virtually synonymous.