The present invention relates to methods and articles for anchoring within a natural bodily lumen. An anchor is adapted to provide differing radially-outward forces along its length, a securing force and a transitional force. Production of these forces can be controlled by varying a physical property of the anchor, such as its stiffness, thickness, or shape. For example, the stiffness of an elongated anchor can be varied from a relatively soft value at its proximal and distal ends to a relatively stiff value at its center by varying the diameter of wire forming the anchor, thereby tailoring it to an intended application. Such force tailoring can be combined with external barbs and used to reliably anchor other instruments, such as feeding tubes and intestinal sleeves.
