A multi-functional endoscopic probe apparatus to selectively apply either a low or high frequency voltage to cut and cauterize. The apparatus has an elongated multi-lumen tube that is attached to a pistol grip having a multiplicity of functions contained thereon. The multi-lumen tube has a first lumen for the passage of either a high or a low pressure irrigation stream therethrough, a second lumen for suction to remove excess fluid and debris, and a third lumen for the passage of a slidably extendable and retractable electro-surgical cutting tip. The pistol grip handle has a wheel which enables the surgeon to rotate the multi-lumen tube containing the surgical cutting tip relative to the pistol grip. A plurality of push-button valves enable the selective application a negative pressure for withdrawing excess fluids and removing incident tissue debris from the surgical site and to operatively apply a flood irrigation stream or a precise irrigation stream to the surgical site to wash and cleanse the tissue. A multi-position electric switch directs either a low or a high frequency voltage to an electro-surgical cutting tip in order to cut and/or cauterized the tissue in contact therewith.