Irritable bowel syndrome is a dysfunction in the digestive system that largely affects the large intestine or the colon. This is the part of the system that takes care of the bowel movements in the body including the storage and the excretion of solid waste materials. In irritable bowel syndrome, the large intestine becomes very sensitive. As to what’s the reason behind the sensitiveness of the large intestine, scientists and medical experts still cannot determine why. Research are still being made up until now to ascertain the true cause of irritable bowel syndrome.