An electrosurgical apparatus for coagulating tissue includes an elongated flexible tube having a proximal end, a distal end, and at least one aperture located therein. The proximal end of the tube receives a supply of pressurized ionizable gas and is disposed within a working channel of the endoscope. At least one electrode ionizes the gas prior to the gas exiting the aperture of the tube and an agitator causes the gas to exit the tube with predetermined flow characteristics. In one embodiment, the agitator includes a helically-shaped baffle disposed within the tube. In another embodiments, the agitator can include a rotatable baffle having apertures disposed therethrough for causing the gas to exit the tube in a swirl-like manner. Alternatively, a pair of elongated ribbons can be disposed within the tube which, under flow conditions, will cause turbulence within the gas flow.