During colonoscopy, four mucosal biopsies will be obtained from normal appearing mucosa in the ascending colon, transverse colon, and descending/sigmoid colon during the withdrawal phase of the exam from each patient (12 research biopsies). To improve orientation 2 biopsies from each segment will be flattened onto filter paper using a forceps and placed together into fixative. The remaining 2 biopsies from each area will be rinsed in sterile PBS to ensure there is no contamination with fecal bacteria prior to freezing in liquid nitrogen.