Individuals with PI-IBS suffer from recurrent, debilitating abdominal pain and altered bowel function (diarrhea and/or constipation) and symptoms can be present for over 8 years after the acute IGE episode is over. It is estimated that up to 15% of the United States population suffers from IBS. This disorder creates significant impact on patient's daily functioning, overall quality of life and causes loss of work productivity. Despite the impact of this illness, treatment options for IBS have limited success, with a significant unmet need. Lack of understanding of underlying pathophysiological mechanisms has hampered development of effective treatment. More studies are required to enhance understanding of this disorder. Development of PI-IBS after an episode of acute IGE serves as a unique model to study risk-factors and mechanisms underlying PI-IBS and IBS in general. The researchers propose to study the epidemiological risk factors and pathophysiological mechanisms involved in the development of IBS among individuals suffering from episodes of acute IGE in the community.