Irritable bowel syndrome (IBS) is the most common cause of consultation in the clinical practice of gastroenterology, and a significant health issue given its chronic nature and interference with health-related quality of life (HRQOL), which patients perceive as moderate to severe. It is characterized by abdominal pain and distension associated with disordered bowel habits (diarrhea, constipation, alternating habit) that persist or relapse for many years, starting during early youth in a proportion of patients. In 20-30% of cases disease onset is related to a recent history of acute, usually bacterial gastroenteritis. It allegedly affects 11-15% of the adult population -depending on the various diagnostic criteria used-mainly between 18 and 65 years of age, and is 2-3 times more common in women than in men, albeit this is not the case in all countries (1-3). This is a chronic disorder and fewer than 10% of patients remain asymptomatic at ten years after diagnosis. While the disorder does not impair patient survival, its relapsing character and severe impact on all HRQOL dimensions, primarily vitality, work, leisure, traveling, and social interactions,