Tissue manipulation devices are disclosed. In various forms, the devices include tissue manipulation arms that are arranged in a position suitable to enable the device to be inserted into the colon then, upon application of at least one actuation motion thereto, at least some of the tissue manipulation arms are moved to deployed positions wherein they contact corresponding portions of the colon to thereby expand the colon. Various devices are actuatable by various forms of actuation forces. In various embodiments, the tissue manipulation arms may be movable along corresponding axes that are transverse to an insertion axis and may also be rotated about the insertion axis as well as be moved in directions that are substantially parallel to the insertion axis.