Lower GI Series
Article provided by the National Digestive Diseases
A lower gastrointestinal (GI) series uses x rays to diagnose
problems in the large intestine, which includes the colon
and rectum. The lower GI series may show problems like
abnormal growths, ulcers, polyps, and diverticuli, and colon
Before taking x rays of your colon and rectum, the
radiologist will put a thick liquid called barium into your
colon. This is why a lower GI series is sometimes called a
barium enema. The barium coats the lining of the colon and
rectum and makes these organs, and any signs of disease in
them, show up more clearly on x rays. It also helps the
radiologist see the size and shape of the colon and rectum.
You may be uncomfortable during the lower GI series. The
barium will cause fullness and pressure in your abdomen and
will make you feel the urge to have a bowel movement.
However, that rarely happens because the tube used to inject
the barium has a balloon on the end of it that prevents the
liquid from coming back out.
You may be asked to change positions while x rays are taken.
Different positions give different views of the intestines.
After the radiologist is finished taking x rays, you will be
able to go to the bathroom. The radiologist may also take an
x ray of the empty colon afterwards.
A lower GI series takes about 1 to 2 hours. The barium may
cause constipation and make your stool turn gray or white
for a few days after the procedure
The digestive system
Preparation for a lower GI
Your colon must be empty for the procedure to be accurate.
To prepare for the procedure you will have to restrict your diet
for a few days beforehand. For example, you might be able to
drink only liquids and eat only nonsugar, nondairy foods for 2
days before the procedure; only clear liquids the day before;
and nothing after midnight the night before. A liquid diet means
fat-free bouillon or broth, gelatin, strained fruit juice,
water, plain coffee, plain tea, or diet soda. To make sure your
colon is empty, you will be given a laxative or an enema before
the procedure. Your physician may give you other special