This book examines new research on irritable bowel syndrome, also known as spastic colon, which is a functional bowel disorder characterised by chronic abdominal pain, discomfort, bloating and alteration of bowel habits in the absence of any organic cause. As discussed in this book, although there is no known cure, symptoms can often be relieved through bowel movements and through certain treatments including dietary adjustments, medication and psychological interventions. Irritable bowel syndrome may begin after an infection or a stressful life event. However, the exact cause of irritable bowel syndrome is unknown. This book examines the most common theory, which states that it is a disorder of the interaction between the brain and the gastrointestinal tract, although there may also be abnormalities in the gut flora or the immune system as well. Some researchers have also suggested that irritable bowel syndrome is a type of low-grade inflammatory bowel disease.