Rectal Biopsy


A rectal biopsy is a procedure to remove a small piece of tissue from the rectum for examination.

Alternative Names

Biopsy - rectum; Rectal bleeding - biopsy; Rectal polyps - biopsy; Amyloidosis - rectal biopsy; Crohn disease - rectal biopsy; Colorectal cancer - biopsy; Hirschsprung disease - rectal biopsy

How the Test is Performed

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.

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.

Normal Results

The anus and rectum appear normal in size, color, and shape. There should be no evidence of:

  • Bleeding
  • Polyps
  • Hemorrhoids
  • Other abnormalities

No problems are seen when the biopsy tissue is examined under a microscope.

What Abnormal Results Mean

This test is a common way to determine the specific causes of abnormal conditions of the rectum, such as:

  • Abscesses
  • Colorectal polyps
  • Infection
  • Inflammation
  • Tumors
  • Amyloidosis
  • Crohn disease
  • Hirschsprung disease in infants
  • Ulcerative colitis


Risks of a rectal biopsy include bleeding and tearing.


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.

Review Date: 9/17/2016

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright ©2017 A.D.A.M., Inc., as modified by University of California San Francisco. Any duplication or distribution of the information contained herein is strictly prohibited.

Information developed by A.D.A.M., Inc. regarding tests and test results may not directly correspond with information provided by UCSF Medical Center. Please discuss with your doctor any questions or concerns you may have.