Definition, epidemiology, diagnosis, natural history

Abstract

SUMMARY
Irritable Bowel Syndrome (IBS) is considered part of a
broader spectrum of symptoms, known collectivelly as functional
abdominal disorders. It is characterized by abdominal
pain associated with defecation or a change in bowel
habit, with features of disordered defecation and distention.
IBS is a remarkably common condition affecting up
to 20% of the general population with a female predominance,
depending on the diagnostic criteria used and the
weight given to various symptoms. The incidence of the disease
has been estimated at almost 1% per year. Although
only a minority of people with IBS seek medical advice, IBS
is the most common disorder seen in gastroenterology practice.
To date no structural or pathophysiological abnormality
has been discovered to explain IBS symptoms. Therefore,
consensus-based diagnostic criteria are at present used for
a positive diagnosis of IBS on clinical grounds. The initial
approach also includes physical examination and a conservative
set of screening studies but upon specific indications,
further investigation may be required. Once the
diagnosis is established, the incidence of serious organic
diseases is extremely low. Nevertheless, IBS is considered
a chronic, although benign, disorder, with variable course
in the general population, and significant impact on quality
of life.
Key words: Irritable bowel syndrome (IBS), prevalence, incidence,
diagnostic criteria, prognosis.