A rectal biopsy is a procedure to remove a small piece of tissue from the rectum for examination.
A rectal biopsy is usually part of anoscopy or sigmoidoscopy. These are procedures to view inside the rectum.
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.
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.
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.
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 (rare disorder in which abnormal proteins build up in tissues and organs).
The anus and rectum appear normal in size, color, and shape. There should be no evidence of:
No problems are seen when the biopsy tissue is examined under a microscope.
This test is a common way to determine the specific causes of abnormal conditions of the rectum, such as:
Risks of a rectal biopsy include bleeding and tearing.
Reviewed By: 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, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.