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