In this article we present a protocol for the use of the low-FODMAP diet in paediatric patients and review of the current evidence on its efficacy. These short-chain carbohydrates, which can be fermented by the intestinal microbiota, are found in a wide variety of foods, mainly of plant origin. The low-FODMAP diet is a therapeutic tool used for the management of gastrointestinal disorders such as irritable bowel syndrome. The sources we used were PubMed, Web of Science, Google Scholar and institutional websites. Following consumption of FODMAP-rich foods, a series of end products are generated that are not absorbed, giving rise to symptoms. Before starting a low-FODMAP diet, it is important to carry out a diagnostic evaluation including any applicable tests. Treatment is structured in 3 phases: elimination, reintroduction and personalization phase. In the first phase, FODMAP-rich foods are eliminated for 2-3 weeks. In the second phase, lasting 8 weeks, FODMAP-rich foods are gradually reintroduced. The last phase consists in customizing the diet according to individual tolerance. This article details which foods contain FODMAPs and possible substitutes. In addition, specific food diary/intake tracking and educational materials are provided in a series of appendices to facilitate adherence to the diet. Although most studies have been conducted in adults, there is also some evidence on the beneficial effects in the paediatric age group, with a reduction of symptoms, especially in patients with functional gastrointestinal disorders. Nevertheless, more research is required on the subject.