Rectal biopsy can be used to determine the cause of blood, mucus, or pus in the stool. Rectal biopsy can also confirm findings of another test or x-rays, or take a biopsy of a growth found in the colon.
Update Date 8/1/2015
Updated by: Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.