Otilonium bromide is a quaternary salt of ammonium which has spasmolytic activity in GI and is widely used for irritable bowel syndrome therapy. This compound relaxes GI smooth muscle mainly through specific inhibition of calcium ion influx, namely on type L calcium channels. The effect of otilonium bromide spasmolytic, without showing the nature of the origin of the agonist, is more visible in the gastrointestinal smooth muscle than in the blood vessels or respiratory system.