ADVANCEMENT TECHNIQUES FOR GASTROINTESTINAL TOOL WITH GUIDING ELEMENT

Gastrointestinal apparatus (200) is provided for use with a fluid pressure source (240). The gastrointestinal apparatus (200) includes a guiding element (214), adapted to be inserted into a colon, and a piston head (220) coupled to a distal portion of the guiding element (214). The piston head (220) is adapted to be inflated to form a first pressure seal between the piston head (220) and a wall of the colon after the guiding element (214) has been inserted into the colon, and be advanced distally through the colon in response to pressure from the fluid pressure source (240) applied to an external surface of the piston head (220). The apparatus (200) further includes a gastrointestinal tool (210) adapted to be advanced along the guiding element (214), and an annular balloon (228) coupled around a distal portion of the gastrointestinal tool (210), the balloon (228) expandable to form a second pressure seal between the distal portion of the gastrointestinal tool (210) and the wall of the colon. Other embodiments are also described.