A rectal biopsy is a procedure to remove a small piece of rectal tissue for examination.
Biopsy - rectum
How the test is performed
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 bowels.
How the test will feel
There will be some discomfort during the procedure, and you may feel an urge to have a bowel movement. Cramping sometimes occurs as the instrument is placed into the rectal area.
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 bleeding, polyps, hemorrhoids, or other abnormalities. When biopsy tissue is examined under a microscope, no abnormalities should be noted.
What abnormal results mean
This test is one of the more common ways to confirm amyloidosis. It also determines the specific causes of abnormal conditions of the rectum, such as colitis. Other findings could include:
The test may be also performed for:
What the risks are
There is some risk of bleeding and tearing. Occasionally, patients have problems with urinary retention and an inability to urinate after rectal biopsy.
Reviewed By: Christine Lee, MD, Department of Surgery, Marin General Hospital, Greenbrae, CA. Review provided by VeriMed Healthcare Network. Also reviewed byDavid Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.