About Trimebutine Antimuscarinic, a noncompetitive spasmolytic agent, In Irritable bowel syndrome (spastic colon). Mechanism of Action of Trimebutine Trimebutine is a noncompetitive spasmolytic agent. It slows down the movement of the bowel and therefore it is used for the treatment of irritable bowel syndrome. Indications for Trimebutine 1.Irritable bowel syndrome Typical Dosage for Trimebutine Oral Adult:600 mg/day in 2 - 3 divided doses before meals Storage Requirements for Trimebutine