Describe the epidemiology.
Prevalence: 10–20% in North America and Europe (accounts for 20–50% of referrals to gastroenterologists)
Sex: In Western countries, women are 1.5–2 times more likely to be affected than men.
Age: highest prevalence in individuals aged 20–39
Somatic pain syndromes: fibromyalgia, chronic fatigue syndrome, functional chest pain
Psychiatric disorders: major depressive disorder, anxiety disorder, somatization disorder
Gastrointestinal disorders: GERD, functional dyspepsia
Describe the pathophysiology.
IBS is a functional gastrointestinal disorder without a specific organic cause. The pathophysiological processes leading to IBS are multifaceted and not yet fully understood. The most common findings associated with IBS are:
Altered gastrointestinal motility
Altered permeability of the gastrointestinal mucosa