Fructose malabsorption, formerly named "dietary fructose intolerance" (DFI), is a digestive disorder in which absorption of fructose is impaired by deficient fructose carriers in the small intestine's enterocytes. This results in an increased concentration of fructose in the entire intestine.
Occurrence in patients identified to be suffering symptoms of irritable bowel syndrome is not higher than occurrence in the normal population. However, due to the similarity in symptoms, patients with fructose malabsorption often fit the profile of those with irritable bowel syndrome. A small proportion of patients with both fructose malabsorption and lactose intolerance also suffer from celiac disease.
Fructose malabsorption is not to be confused with hereditary fructose intolerance, a potentially fatal condition in which the liver enzymes that break up fructose are deficient.