A digital rectal exam is done first. Then, a lubricated instrument (anoscope or proctoscope) is placed into the rectum. You will feel some discomfort when this is done.
A biopsy can be taken through any of these instruments.
How to Prepare for the Test
You may get a laxative, enema, or other preparation before the biopsy so that you can completely empty your bowel. This will allow the doctor a clear view of the rectum.
How the Test will Feel
There will be some discomfort during the procedure. You may feel like you need to have a bowel movement. You may feel cramping or mild discomfort as the instrument is placed into the rectal area. You may feel a pinch when a biopsy is taken.
Why the Test is Performed
A rectal biopsy is used to determine the cause of abnormal growths found during anoscopy, sigmoidoscopy, or other tests. It can also be used to confirm the diagnosis of amyloidosis.
The anus and rectum appear normal in size, color, and shape. There should be no evidence of:
Debra G. Wechter, MD, FACS, general surgery practice specializing in breast cancer, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.