An imidazole compound of the formula: wherein Ring A is benzene or a heterocyclic ring; G is alkylthio, alkylsulfonyl, optionally substituted phenyl, or optionally substituted heterocyclic ring group, etc.; Ring C is imidazole; R.sup.1 is carbamoyl, etc.; R.sup.2 is cyano, nitro, hydroxyl, an alkoxy, a halogen, carboxy, an alkoxycarbonyl, carbamoyl, amino, an alkyl, etc.; m is 0 to 2; and R.sup.4 is hydrogen, an alkyl, etc., or a pharmaceutically acceptable salt thereof, is a large conductance calcium-activated K channel opener useful for treatment of pollakiuria, urinary incontinence, etc.