[The proven and the new in the pharmacotherapy of irritable bowel syndrome].

Irritable bowel syndrome (IBS) is a chronic disease of the digestive tract that is characterised by decades-long chronicity. At the same time, it is particularly challenging to treat since successful treatment often requires a combination of pharmacological and non-pharmacological measures. The pathomechanisms of IBS have only just started to be elucidated, meaning that causally effective treatments are largely lacking. In contrast to earlier notions of a "psychosomatic disorder", IBS is an organic disease in the vast majority of cases. The predominant symptoms are usually intestinal cramps or abdominal pain, meteorism/flatulence, constipation, and diarrhea. The patient should be fully included in a joint treatment concept from the outset. Given the lack of causal treatment methods, each treatment approach is initially by way of trial; if there is no effect, treatment should be discontinued after 3 months at the latest. Effective treatments can be continued, adapted, and/or combined with other procedures as an on-demand or permanent treatment. Supplementing the targeted drug treatment of the dominant individual symptoms with somewhat unspecific but often relevantly effective basic or accompanying treatments has proven useful. Such a multimodal treatment strategy, in which general measures as well as nutritional, psychological, and pharmacotherapies are individually combined, is significantly superior to drug monotherapy. This article describes first- and second-line drug treatments in addition to options for refractory symptoms. The choice of drug therapy is primarily determined by the dominant symptoms. Depending on the symptom constellation, it may be beneficial to combine different drugs.