A rectal biopsy is a procedure to remove a small piece of tissue from the rectum for examination.
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 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.
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.
The anus and rectum appear normal in size, color, and shape. There should be no evidence of:
- Other abnormalities
No problems are seen when the biopsy tissue is examined under a microscope.
Risks of a rectal biopsy include bleeding and tearing.
What Abnormal Results Mean
This test is a common way to determine the specific causes of abnormal conditions of the rectum, such as:
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.
Weinstein WM. Tissue sampling, specimen handling, and chromoendoscopy. In: Ginsberg GG, Gostout CJ, Kochman ML, Norton ID, eds. Clinical Gastrointestinal Endoscopy. 2nd ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 5.