Reported rates of IBS are typically 1.5- to 3-fold higher in women than men2,3
The prevalence of IBS-D is similar for men and women, while approximately two-thirds of patients diagnosed with IBS-C are women1
The difference in IBS rates between men and women partly reflects differences in health-seeking behavior, as well as differences in willingness to make or accept a diagnosis, rather than the underlying condition2
Female sex hormones and gender differences in viscerosensory perception may, however, play a role in IBS symptom incidence and severity6,7
IBS can occur in all age groups, including children and the elderly, though the majority of patients experience symptoms before age 351,8-10
Patients typically first present to a healthcare professional between the ages of 30 and 50 years11
IBS is known to aggregate in families, and having a mother or father with IBS is an independent risk factor for an individual having IBS12,13
There is no single or dominant gene associated with IBS, though several potential candidate genes have been identified and the estimated genetic liability of IBS ranges from 1% to 20%12
The observation that IBS clusters in families is likely explained at least in part by shared environmental contributors, such as physical or sexual abuse, household stressors (e.g. ill family member or traumatic event), parenting style, and learned illness behavior 2,12
Psychiatric disorders and IBS appear to have bidirectional comorbidities, and approximately 40% of patients with IBS have some degree of psychiatric comorbidity11,14
Many patients with IBS may not have a psychiatric illness per se, but may manifest psychoform symptoms and somatoform complaints15,16
Approximately 50% of patients with IBS suffer from an additional functional disorder2