How can we develop better antispasmodics for irritable bowel syndrome?

INTRODUCTION: Irritable bowel syndrome (IBS) is a prevalent gastrointestinal (GI) disease. Antispasmodics are a heterogeneous group of drugs that tackle IBS-associated altered bowel habit and abdominal pain. However, some studies have shown their failure to exhibit benefit over placebo. Considering the place of antispasmodics in managing key symptoms of IBS, there is a growing need for developing more efficacious and safe antispasmodics. Areas covered: The authors discuss the role of rational drug design (RDD) in developing new antispasmodics with desired features. Furthermore, they review the potential pharmacological targets and herbal medicines with spasmolytic activity. In addition, the authors present the recent findings concerning novel mechanisms involved in GI motility modulation as well as the potential antispasmodic role of drugs used in other conditions. Expert opinion: To develop better antispasmodics, it will be essential to gain a deeper insight into the underlying mechanisms involved in IBS-induced dysmotility and to uncover GI-specific receptors that regulating motility. New antispasmodics with GI-restricted and the multi-targeting features can be developed via implementation of RDD. Furthermore, the modification of current antispasmodics by formulation technologies might expedite the development of better antispasmodics. To conclude, the complex nature of IBS means that future successful drug discovery will require a multi-disciplinary approach.