methods of accessing and ablating abnormal epithelium tissue in an alimentary canal are provided . the methods can include steps of inserting a vacuum source comprising one or more suction ports into an alimentary canal ; inserting an operative element comprising a conduit for a tissue ablation source into the alimentary canal ; positioning the vacuum source and the operative element proximate a portion of the alimentary canal having a site of abnormal tissue to be ablated ; applying a vacuum to at least one of each suction port to draw the tissue against the operative element ; and applying the tissue ablation source to the tissue through the conduit to effect tissue ablation .