Methods and apparatus for the endoluminal revision of previously performed obesity procedures which have failed are described. One or more endoluminal instruments may be advanced per-orally into the previously formed failed pouch where a number of different procedures can be performed. One or more tissue folds can be formed and secured to reduce the size of the pouch, or the stoma connecting the pouch to the intestinal tract can be reduced in size using endoluminally deployed tissue anchors. These procedures can be performed entirely from within the pouch lumen or upon the exterior surface of the pouch via transgastric entry of the instruments into the peritoneal cavity of a patient. Alternatively, the interior tissue within the pouch can be injured or sclerosed to shrink the pouch lumen. In another alternative, a length of the Roux limb can be shortened endoluminally to create a malabsorptive region.