Gender Differences in Irritable Bowel Syndrome

Publisher Summary Irritable bowel syndrome (IBS) is a common digestive disorder characterized by abdominal discomfort and altered bowel habits. Although the mechanisms are not entirely clear, IBS disproportionately affects women and men at a ratio of over 2:1. The complex interplay between IBS, sex, and gender has intrigued the medical community for decades, giving rise to many theories why IBS affects women and men differently. Some have proposed that the greater prevalence of IBS in women merely reflects an underestimation of prevalence in men due to symptom under-reporting. Others have implicated psychosocial, anatomical, and biochemical factors such as a history of personal abuse, gastrointestinal tract anatomic or physiologic differences in disease expression, and symptom perception. This chapter explores the multiple possibilities why IBS is more commonly diagnosed in women. IBS is a clinical diagnosis based on fulfillment of the Rome III criteria, which were originally established for investigational purposes. Depending on the predominant symptom, patients are categorized as constipation predominant (IBS-C), diarrhea predominant (IBS-D) or mixed. Each group is equally represented among patients with IBS, although differences exist between women and men in the clinical manifestations of IBS. Constipation is more common in women as are extracolonic symptoms. IBS symptoms are thought to occur as a result of dysregulation of the brain–gut axis, although a single underlying etiology of the disorder remains elusive. Treatment of IBS is individualized and based on the predominant symptom(s).