Why a Barium
The purpose of a barium enema is to demonstrate the anatomy and morphology
of the large intestine. The large intestine frames the abdomen and is
divided into six sections. These include the rectum, sigmoid colon,
descending colon, transverse colon, ascending colon, and cecum.
Anatomy of the Colon
A barium enema may be performed for a variety of reasons, including
abdominal pain or a change in bowel habits such as diarrhea or constipation,
as well as a change in the caliber (size) of the stools. This exam is also
requested when parasites, blood, mucus, or pus are found in the stools.
Occult (hidden) blood found in the stools and anemia may be an indication of
intestinal bleeding due to ulcers, inflammatory disease, or a cancerous
lesion. Doctors may also order this exam as a screening tool for patients
with a history of polyps (pre-cancerous growths extending outward from a
mucous membrane) or a family history of colorectal cancer.
A barium enema may also be requested when the large intestine was not
completely visualized during a colonoscopy (examination of the large intestine with a fiber-optic tube)
or when a sigmoidoscopy is done, which only partially visualizes the colon.
Sometimes a barium enema may be used as a treatment for intussusception
(telescoping of one section of the bowel into another causing obstruction).
This is a rare disorder occuring most often in young children, but when it
occurs immediate action must be taken.
A barium enema may also be done to evaluate the remaining colon on
colostomy patients. The barium is injected into the stoma (external drainage
opening in the abdominal wall) instead of the rectum. A barium enema may be
done if obstruction, perforation, or fistula formation is suspected.