Almost all irritable bowel syndromes are post-infectious and respond to probiotics: controversial issues.

Acute infectious gastroenteritis is the strongest known risk factor for the development of irritable bowel syndrome (IBS), one of the most common functional gastrointestinal disorders. However, knowledge about the incidence and prevalence of post-infectious IBS (PI-IBS) in the general population is still limited. Some of the published epidemiological studies on PI-IBS lack an appropriate control population, and were limited by a short follow-up symptom assessment post-infection. A number of risk factors have been associated with the development of PI-IBS, including the virulence of the pathogen, younger age, female sex, the long duration of the initial illness and the presence of psychological disturbances. However, much work has to be done to establish whether multifactorial mechanisms actually concur to the pathophysiology of PI-IBS. The discovery that an infective episode may trigger the development of IBS has not substantially changed the clinical management of this subset of patients compared to the classical (non-infective) form of IBS. Probiotics have been claimed to be of some benefit in IBS, but the majority of studies have been performed in non-specific IBS rather than in PI-IBS and a number of issues still remain to be elucidated.