Irritable bowel syndrome (IBS) is a common functional disorder and may lead to impaired social and personal function and can diminish quality of life.While the precise pathophysiology of IBS remains to be elucidated, dysmotility and altered visceral sensory perception are currently the most popular hypothesis. There has been a suggestion that some patients with IBS may harbor bacterial overgrowth leading to low grade inflammation, immune activation, and their symptoms may be ameliorated by its eradication.Probiotics, defined as live or attenuated bacteria or micro organism that confer a significant health benefit to the host.