Fructose malabsorption can be diagnosed using a hydrogen and/or methane breath tests, which recognise unabsorbed fructose. The foods we eat are made up of many components, including sugars. Fructose is a sugar found naturally in many foods, including honey, wheat, fruits and vegetables. Fructose is present in a single sugar form and also as a chain of fructose sugar units (fructans). Normally, fructose is absorbed in the small bowel. In fructose malabsorption, the normal absorption of fructose is impaired. Fructose malabsorption can cause symptoms of stomach bloating, wind, stomach pain, loose bowel motions and / or constipation if the diet is not well planned. These are common symptoms that can often be called irritable bowel syndrome.
Not every food that contains fructose is a problem for people with fructose malabsorption. It is important to understand how fructose occurs in foods to know which foods are suitable to eat, and which foods should be limited.
It is advisable to speak with a dietitian with experience in Fructose Malabsorption to have the dietary treatment fully explained. People with Fructose Malabsorption are taught the Low FODMAP Diet as symptoms are not usually caused by fructose malabsorption alone – other FODMAPs often contribute to symptoms, and therefore dietary education re: restriction of all FODMAPs is usually recommended.