A method of performing a bariatric procedure through a natural body orifice is disclosed. The method comprises the step of providing a surgical instrument, comprising a handle portion, an elongated portion extending distally from the handle portion, and an end effector disposed adjacent a distal end of the elongated portion. The method also comprises the steps of inserting the surgical instrument through a natural body orifice of a patient such that the end effector is adjacent a portion of the patient's stomach, and using the surgical instrument to perform a surgical task.