The glucose group will serve as a control since glucose is not a FODMAP and as a result is not expected to lead to recurrent symptoms. The glucose/fructose mixture group is a cross comparison group that will determine whether the relative excess fructose concentration is an important cause of IBS symptoms. Fructose absorption in the gut is dependent on glucose intake as fructose is transported with glucose from inside the gut into the body. Current studies suggest that fructose intolerance in healthy controls is highly dependent on the ratio of excess fructose to glucose.