Summary: Functional gastrointestinal disorders (FGIDs) are a group of conditions, or rather complaints, that are not caused by any organic or metabolic damage to the gastrointestinal tract. The pathomechanism of the changes is very complex. They are currently attributed to dysfunction of the bidirectional brain- -gut axis. In addition, genetic factors, environmental factors and intestinal dysbiosis, which has complex causes, such as intestinal infections, including COVID-19, are mentioned. The most common form of FGIDs is irritable bowel syndrome (IBS). Treatment of CZPP and its associated symptoms is multidirectional. It also includes probiotics such as Lactiplantibacillus plantarum 299v. This probiotic strain is the best documented L. plantarum strain in the world. Data from various stages of research indicate beneficial effects of this probiotic primarily in alleviating and removing symptoms (e.g. abdominal pain, bloating, nausea, motility disorders etc.) of functional gastrointestinal diseases in children and adults. Currently, the strain is available in the form of oral drops and – as safe and effective – can be administered to children after the age of 1. This creates a wide range of other possibilities for its use (besides FGIDs) in pediatric practice.