Methods and devices for use in tissue approximation and fixation are described herein. The present invention provides, in part, methods and devices for acquiring tissue folds in a circumferential configuration within a hollow body organ, e.g., a stomach, positioning the tissue folds for affixing within a fixation zone of the stomach, preferably to create a pouch or partition below the esophagus, and fastening the tissue folds such that a tissue ring, or stomas, forms excluding the pouch from the greater stomach cavity. The present invention further provides for a liner or bypass conduit which is affixed at a proximal end either to the tissue ring or through some other fastening mechanism. The distal end of the conduit is left either unanchored or anchored within the intestinal tract. This bypass conduit also includes a fluid bypass conduit which allows the stomach and a portion of the intestinal tract to communicate.