A full-thickness resection system is disclosed. In an embodiment for the resection system, the system may include a flexible shaft, a flexible guide member disposed within the flexible shaft, a stapling mechanism disposed around the flexible guide member, and a grasper. The stapling mechanism has an elongated portion that is at least partially disposed within the flexible shaft. The stapling mechanism includes a stapling arm and an anvil arm. The stapling arm has a longitudinal axis and includes a stapling head having a longitudinal axis. The anvil includes an anvil head. The stapling arm and anvil arm extend from the elongated portion of the stapling mechanism and are moveable with respect to each other between a tissue receiving position and a stapling position. The grasper extends through the flexible shaft and is adapted to grasp a portion of a tissue that is to be excised from an organ in the patient's body. The grasper is movable on an axis that is perpendicular to the longitudinal axis of the stapling head.