An integrated catheter assembly for enabling diverse endoscopic in situ therapies. The assembly includes a catheter with an irrigation fluid lumen, a distal electrode tip portion that acts as a hemostat, and a cutting wire for making incisions in or ablating tissue. A cutting wire hub provides a sealing entrance for a cutting wire. An operator enables the physician to displace the cutting wire between extended and retracted positions. The cutting wire and electrode are electrically isolated. In addition, the catheter assembly may include a planar tip which, when extended outside the distal end of the assembly, assumes a substantially flat unbiased configuration for use. The apparatus of the present invention allows the physician to make incisions in or ablate tissue using electrosurgery, irrigate tissue, and cauterize or coagulate tissue without having to remove the apparatus from the working channel of the endoscope.