Barium enema
Encyclopedia
A lower gastrointestinal series, also called a barium enema, is a medical procedure used to examine and diagnose problems with the human colon
(large intestine). X-ray
pictures are taken while barium sulfate
fills the colon via the rectum.
tube is inserted into the rectum
. As the enema enters the body, the patient might have the sensation that they have to have a bowel movement. The barium sulfate, a radiopaque
(shows up on X-ray) contrast medium
, is then allowed to flow into the colon. A small balloon at the tip of the enema tube may be inflated to help keep the barium sulfate inside. The flow of the barium sulfate is monitored by the health care provider on an X-ray fluoroscope screen (like a TV monitor). Air may be puffed into the colon to distend it and provide better images (often called a "double-contrast" exam). If air is used, the enema tube will be reinserted (if it had been removed; whether it is depends on who does the exam) and a small amount of air will be introduced into the colon, and more X-ray pictures are taken.
The patient is usually asked to move to different positions and the table is slightly tipped to get different views.
If there is a suspected bowel perforation, a water-soluble contrast
is used instead of barium. The procedure is otherwise very similar, although the images are not quite as good. (The concern with existing perforation is that contrast will leak from the bowel to the peritoneal cavity
, and water-soluble material, compared to barium is less obscuring at laparotomy.)
(a laxative), and warm water enemas to clear out any stool particles.
Barium enemas are most commonly used to check bowel health; they can help diagnose and evaluate the extent of inflammatory bowel diseases such as ulcerative colitis
and Crohn's disease
. Polyps
can be seen, though not removed during the exam like with a colonoscopy
— they may be cancerous. Other problems such as diverticulosis
(small pouches formed on the colon wall that can become inflamed) and intussusception
can be found (and in certain cases the test itself can treat intussusception). An acute appendicitis
or twisted loop of the bowel may also be seen. If the picture is normal a functional cause such as irritable bowel syndrome
(IBS) may be considered.
In a healthy colon, barium should fill the colon uniformly and show normal bowel contour, patency (should be freely open), and position.
Additional conditions under which the test may be performed:
than an abdominal CT. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most experts feel that the risk is low compared with the benefits. Pregnant women and children are more sensitive to the risks of ionizing radiation.
A more serious risk is a bowel perforation.
s are now the tests of choice for the initial evaluation of abdominal masses, and colonoscopies are becoming the standard for routine colon screening for those over age 50 or with a familial history of polyps or colon cancer, although it is not uncommon for a barium enema to be done after a colonoscopy for further evaluation.
Colon (anatomy)
The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
(large intestine). X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
pictures are taken while barium sulfate
Barium sulfate
Barium sulfate is the inorganic compound with the chemical formula BaSO4. It is a white crystalline solid that is odorless and insoluble in water. It occurs as the mineral barite, which is the main commercial source of barium and materials prepared from it...
fills the colon via the rectum.
Procedure
This test may be done in a hospital or clinic. The patient lies on the X-ray table and a preliminary X-ray is taken. The patient is then asked to lie on the side while a well lubricated enemaEnema
An enema is the procedure of introducing liquids into the rectum and colon via the anus. The increasing volume of the liquid causes rapid expansion of the lower intestinal tract, often resulting in very uncomfortable bloating, cramping, powerful peristalsis, a feeling of extreme urgency and...
tube is inserted into the rectum
Rectum
The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
. As the enema enters the body, the patient might have the sensation that they have to have a bowel movement. The barium sulfate, a radiopaque
Radiodensity
Radiodensity refers to the relative inability of electromagnetic radiation, particularly X-rays, to pass through a particular material. Radiolucency indicates greater transparency or "transradiancy" to X-ray photons...
(shows up on X-ray) contrast medium
Radiocontrast
Radiocontrast agents are a type of medical contrast medium used to improve the visibility of internal bodily structures in an X-ray based imaging techniques such as computed tomography or radiography...
, is then allowed to flow into the colon. A small balloon at the tip of the enema tube may be inflated to help keep the barium sulfate inside. The flow of the barium sulfate is monitored by the health care provider on an X-ray fluoroscope screen (like a TV monitor). Air may be puffed into the colon to distend it and provide better images (often called a "double-contrast" exam). If air is used, the enema tube will be reinserted (if it had been removed; whether it is depends on who does the exam) and a small amount of air will be introduced into the colon, and more X-ray pictures are taken.
The patient is usually asked to move to different positions and the table is slightly tipped to get different views.
If there is a suspected bowel perforation, a water-soluble contrast
Radiocontrast
Radiocontrast agents are a type of medical contrast medium used to improve the visibility of internal bodily structures in an X-ray based imaging techniques such as computed tomography or radiography...
is used instead of barium. The procedure is otherwise very similar, although the images are not quite as good. (The concern with existing perforation is that contrast will leak from the bowel to the peritoneal cavity
Peritoneal cavity
The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum, that is, the two membranes that separate the organs in the abdominal cavity from the abdominal wall...
, and water-soluble material, compared to barium is less obscuring at laparotomy.)
Preparation
Thorough cleaning of the large intestine is necessary for accurate pictures. Test preparations include a clear liquid diet (some places it is NPO - nihil per os - after midnight), drinking a bottle of magnesium citrateMagnesium citrate
Magnesium citrate, a magnesium salt of citric acid, is a chemical agent used medicinally as a saline laxative and to completely empty the bowel prior to a major surgery or colonoscopy. It is available without a prescription, both as a generic brand or under the brand name Citromag or Citroma. It is...
(a laxative), and warm water enemas to clear out any stool particles.
Purpose
Ulcerative colitis
Ulcerative colitis is a form of inflammatory bowel disease . Ulcerative colitis is a form of colitis, a disease of the colon , that includes characteristic ulcers, or open sores. The main symptom of active disease is usually constant diarrhea mixed with blood, of gradual onset...
and Crohn's disease
Crohn's disease
Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...
. Polyps
Polyp (medicine)
A polyp is an abnormal growth of tissue projecting from a mucous membrane. If it is attached to the surface by a narrow elongated stalk, it is said to be pedunculated. If no stalk is present, it is said to be sessile. Polyps are commonly found in the colon, stomach, nose, sinus, urinary bladder...
can be seen, though not removed during the exam like with a colonoscopy
Colonoscopy
Colonoscopy is the endoscopic examination of the large bowel and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It may provide a visual diagnosis and grants the opportunity for biopsy or removal of suspected...
— they may be cancerous. Other problems such as diverticulosis
Diverticulosis
Diverticulosis also known as "diverticular disease" is the condition of having diverticula in the colon, which are outpocketings of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. These are more common in the sigmoid colon, which is a common place for...
(small pouches formed on the colon wall that can become inflamed) and intussusception
Intussusception (medical disorder)
An intussusception is a medical condition in which a part of the intestine has invaginated into another section of intestine, similar to the way in which the parts of a collapsible telescope slide into one another. This can often result in an obstruction...
can be found (and in certain cases the test itself can treat intussusception). An acute appendicitis
Appendicitis
Appendicitis is a condition characterized by inflammation of the appendix. It is classified as a medical emergency and many cases require removal of the inflamed appendix, either by laparotomy or laparoscopy. Untreated, mortality is high, mainly because of the risk of rupture leading to...
or twisted loop of the bowel may also be seen. If the picture is normal a functional cause such as irritable bowel syndrome
Irritable bowel syndrome
Irritable bowel syndrome is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, the symptoms are relieved by bowel movements...
(IBS) may be considered.
In a healthy colon, barium should fill the colon uniformly and show normal bowel contour, patency (should be freely open), and position.
Additional conditions under which the test may be performed:
- CMV gastroenteritis/colitisColitisIn medicine, colitis refers to an inflammation of the colon and is often used to describe an inflammation of the large intestine .Colitides may be acute and self-limited or chronic, i.e...
- Hirschsprung's diseaseHirschsprung's diseaseHirschsprung's disease , or congenital aganglionic megacolon is a serious medical problem where the enteric nervous system is missing from the end of the bowel. The enteric nervous system is a complex network of neurons and glia that controls most aspects of intestinal function...
- intestinal obstruction
- intussusception (children)
Risks
There is less radiation exposureRadiation exposure
The term radiation exposure commonly has several uses:* Absorption of high-energy ionizing radiation by an object. In living beings a high absorbed dose can lead to radiation poisoning.* Absorption by an object of non-ionizing radiation...
than an abdominal CT. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most experts feel that the risk is low compared with the benefits. Pregnant women and children are more sensitive to the risks of ionizing radiation.
A more serious risk is a bowel perforation.
Special considerations
CT scans and ultrasoundUltrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
s are now the tests of choice for the initial evaluation of abdominal masses, and colonoscopies are becoming the standard for routine colon screening for those over age 50 or with a familial history of polyps or colon cancer, although it is not uncommon for a barium enema to be done after a colonoscopy for further evaluation.
External links
- Duplicated Colon on Barium Enema - MedPix Medical Image Database
- RadiologyInfo - The radiology information resource for patients: Barium Enema
- NIH page on barium enemas