What Is a Rectal Biopsy?
rectal biopsy is a procedure used to extract a tissue sample from the rectum
for laboratory analysis. The rectum is the lowest 6 inches of the large
intestine, and is located just above the anal canal. Its purpose is to store
the body’s solid waste until it is released.
rectal biopsy is an important tool for determining the causes of abnormalities
in the rectum. It helps to diagnose problems that are identified in screening
tests such as anoscopy or sigmoidoscopy.
and sigmoidoscopy each use a different type of scope to observe the inner
lining of the colon and rectum. The tests can identify the presence of
conditions such as tumors, polyps, bleeding, or inflammation. However, these
tests are limited in determining the causes of these abnormalities. Your doctor
may have to order more tests before they are able to give you a diagnosis.
Diagnostic Uses of a Rectal
physician may recommend a rectal biopsy to:
- identify the
cause of blood, mucus, or pus in your stool
- determine the causes
of tumors, cysts, or masses identified in a rectal screening test
- confirm a
diagnosis of amyloidosis (a condition in which abnormal proteins called
amyloids build up in your organs and spread through your body)
- make a
definitive diagnosis of rectal cancer
Preparation for a Rectal
get the most reliable results from your rectal biopsy, it is necessary for your
physician to see the rectum clearly. This requires that your bowels are empty.
You will typically be given an enema or laxative to help you empty your bowels.
should tell your physician about any prescription or over-the-counter
medications you are taking. Discuss how they should be used before and during
physician may provide special instructions if you are taking medications that
could affect the procedure, especially if your biopsy is part of a
sigmoidoscopy. These medications may include:
anti-inflammatory drugs (NSAIDs), including aspirin or ibuprofen
- any medications
that affect blood clotting
- herbal or
your physician if you are pregnant, or think you might be pregnant, to ensure
that your fetus is not harmed.
The Rectal Biopsy Procedure
rectal biopsy usually is performed during an anoscopy or sigmoidoscopy. These
tests are outpatient procedures typically done by a gastroenterologist or
anoscopy is typically performed in a physician’s office. This test uses a
lighted scope called an anoscope. The scope allows the physician to view the
lowest 2 inches of the anal canal and the lower rectum. A proctoscope, which is
longer than an anoscope, may also be used.
sigmoidoscopy can be performed in a hospital, an outpatient surgical center, or
in a specially equipped physician’s office. This test uses a much longer scope.
A sigmoidoscope enables the physician to see further into the large intestine,
past the rectum, and into the colon. It is a flexible, lighted tube that is
over 2 feet long. It has a camera that transmits video images to a monitor. The
images help the physician guide the sigmoidoscope through the rectum and colon.
for both types of procedures are similar. The sigmoidoscopy, which is the more
complicated procedure, takes about 20 minutes to perform. Taking a rectal
biopsy can slightly extend the time the procedure will take.
general anesthesia, sedatives, and painkilling medication are not administered
for the procedures. You will be positioned lying on your left side on an
examining table. You will pull your knees toward your chest.
doctor will perform a digital rectal examination. A lubricant will be applied
to a gloved finger, which will be inserted gently into your anus. The initial
exam is to check for obstructions that may interfere with the scope. You
shouldn’t feel any pain during the digital rectal examination, but you may feel
pressure. Your physician will then insert the lubricated scope. You will feel
pressure when the scope is inserted and you may feel cramping, as though you
need to pass gas or have a bowel movement.
you are having a sigmoidoscopy, air will be inserted into the colon through the
scope. The air will inflate the colon to allow the physician to see the area
more clearly. If fluid or stools are in the way, your physician may use suction
to remove them. You may be asked to change position to allow the physician to
alter the position of the scope.
physician will remove a sample of any abnormal tissue they find in the rectum.
The biopsy will be extracted with forceps, a brush, swab, or suction catheter.
Typically, a patient does not feel pain from the tissue removal.
or heat, may be used to stop any bleeding that results from tissue being
removed. When the procedure is over, the scope is removed slowly from your
Recovery from a Rectal
degree to which you need to recover will depend on the type of procedure that
was used to collect your rectal biopsy.
a flexible sigmoidoscopy was used, you may experience bloating from the air
that was introduced into the colon. This may result in abdominal discomfort or
passing gas for a few hours after the procedure.
is not uncommon to find a small amount of blood in your first bowel movement
after your rectal biopsy. However, you should contact your physician if you
- more than one
bloody bowel movement, especially if bleeding is heavy or clotted
- a feeling of
can resume your normal diet and activities as soon as the procedure is over.
Risks of a Rectal Biopsy
rectal biopsy can provide valuable data for diagnosing abnormal tissue in the
rectum. In cases where cancer is a concern, the procedure can provide a
a rectal biopsy, like any invasive procedure, carries the risk of internal
damage to the targeted organ or nearby areas. Potential risks of a rectal
perforation (tearing of the bowel)
risks are very rare.
Understanding the Results
of a Rectal Biopsy
tissue sample that was retrieved during your rectal biopsy will be sent to a
laboratory for examination. A pathologist — a physician who specializes in disease
diagnosis — will examine the tissue. A report on the findings will be sent to
the results of your rectal biopsy are normal, the findings will indicate:
- the anus and
rectum are normal in size and appearance
- there is no
- no polyps,
hemorrhoids, cysts, or tumors were found
abnormalities were noted
the results of your rectal biopsy are abnormal, the physician may have found:
- polyps or
other abnormal growths
results of your rectal biopsy also may indicate a positive diagnosis for:
disease: an inflammatory bowel disease that affects the gastrointestinal tract
disease: an intestinal disease that can cause an obstruction
- ulcerative colitis:
an inflammatory bowel disease that affects the colon and rectum
Your doctor may order more laboratory tests or
physical exams before they are able to give you a diagnosis.