Studies examining the prevalence of irritable bowel syndrome (IBS) consistently show that women outnumber men in both patient and nonpatient populations. However, because IBS does affect both women and men, it is important to examine and to understand gender similarities and differences in the expression of this complex disorder. Studies that have explored gender differences have focused their investigations on prevalence and health seeking behavior, physical and psychological symptomotology, and abuse history. This article reviews and summarizes the findings from those studies. As well, whereas the literature examining differences between men and women with IBS has focused on distinctions based on the biological sex of study participants, this article offers an alternate approach to the exploration of gender differences. The concept of gender role, defined as generalizations about appropriate male and female traits that are associated with masculinity and femininity, may further our understanding of IBS in both women and men.