Breath tests are sometimes used to identify people who malabsorb fructose, lactose and/or sorbitol.
Although lactose breath tests are considered a reliable method for identifying lactose malabsorption and useful to guide dietary restrictions of lactose, research shows that the results from fructose breath tests are not reliable. For this reason, we do not recommend that patients use fructose breath tests.
We do suggest that you discuss the advantages and disadvantages of breath tests with your health professional, before proceeding. If you decide not to proceed with breath testing, a 3-step FODMAP diet can be commenced under the guidance of an experienced dietitian. When you get to step 2, your dietitian will guide you through a series of food-based challenges to work out which FODMAPs you tolerate, and which trigger your IBS symptoms.