An apparatus for performing endoluminal anastomosis of an organ comprises an operative head including an endoscope receiving lumen for slidably receiving a flexible endoscope therein, the operative head including an annular tissue receiving space extending around a circumference of a distal end thereof and a stapling mechanism for firing staples around an entire circumference of the tissue receiving space and a tissue gripping mechanism for drawing into the tissue receiving space a portion of tissue extending around an entire circumference of the organ.