Overview

• 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

• Associated conditions

  • Somatic pain syndromes: fibromyalgia, chronic fatigue syndrome, functional chest pain

  • Psychiatric disorders: major depressive disorder, anxiety disorder, somatization disorder

  • Gastrointestinal disorders: GERD, functional dyspepsia

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

• Visceral hypersensitivity/hyperalgesia

• Altered permeability of the gastrointestinal mucosa

• Psychosocial aspects