A proximal housing for a full-thickness resection device (FTRD) is provided with a plurality of chambers through which fasteners are introduced into a portion of tissue to be resected. The proximal housing has a noncircular cutout opposite the plurality of chambers to receive a noncircular endoscope. The proximal housing also is provided with a resection cavity into which the tissue to be resected is to be received. In addition, shaft openings are provided through which mounting shafts may be inserted. A noncircular endoscope is also disclosed for insertion into the cut-out whereby the endoscope has passages to house the functions of remote viewing, illumination, insulation and irrigation.