Lower gastrointestinal series

Lower gastrointestinal series
Lower gastrointestinal series
	Radiograph of a barium enema displaying a colonic herniation.
ICD-9-CM	87.64

Last updated March 16, 2024

A lower gastrointestinal series is a medical procedure used to examine and diagnose problems with the human colon of the large intestine. Radiographs (X-ray pictures) are taken while barium sulfate, a radiocontrast agent, fills the colon via an enema through the rectum.

Purpose

For any suspected large bowel disease, colonoscopy is the investigation of choice because tissue sample can be taken for investigation. Virtual colonoscopy (also known as CT colonography) is another preferred investigation, provided that facilities and expertise are available. Virtual colonoscopy also avoids the risk of total blockage of any stricture in the large bowel due to barium impaction.^[1] Some conditions are absolutely contraindicated for barium enema namely: toxic megacolon, pseudomembranous colitis, and recent history rigid endoscopy of the large bowel in the past five days and recent history of flexible endoscopy in the past 24 hours. This is because, rigid endoscopy tends to use larger biopsy forceps to take tissue samples from the bowel wall while flexible endoscopy uses small biopsy forceps to take superficial samples.^[1] For those with incomplete bowel preparation, the subject can return the next day or the day after next to repeat the procedure. If barium meal was performed recently, then it is advised to wait for another seven to ten days before repeating the procedure. Some frail subject may not be suitable for barium meal.^[1]

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:

CMV gastroenteritis/colitis
Hirschsprung's disease
intestinal obstruction
intussusception (children)

Procedure

Barium enema can be done in two ways, namely double contrast and single contrast methods. Double contrast (where air is inflated into the bowel after excess barium are drained through anus) is useful in visualising mucosal pattern. For single contrast study (whole bowel is filled up with barium without inflating any air), it is used to visualise any obstruction in the large bowel, and it is used in children where visualisation of mucosal pattern is not needed. Barium enema is also used to reduce an intussusception where this disorder is more commonly found in children.^[1] 500 ml of Polibar 150% (barium sulfate suspension) is used to perform this study. Subject should be fasted and Picolax (sodium picosulfate) is taken orally to empty the bowels before barium enema procedure.^[1]

This test may be done in a hospital or clinic. The individual lies on the X-ray table and a preliminary X-ray is taken. The individual is then asked to lie on their side while a well lubricated enema tube is inserted into the rectum. As the enema enters the body, the individual might have the sensation that they need to have a bowel movement. The barium sulfate, a radiodense (shows as white on X-ray) contrast medium, flows through the rectum into the colon. A large 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 and a small amount of air will be introduced into the colon, and more X-ray pictures are taken.

The individual 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 agent (such as diatrizoate) is used instead of barium. The procedure is otherwise very similar, although the images will be of poorer quality. If a perforation exists, the contrast will leak from the bowel to the peritoneal cavity; water-soluble material is less obscuring compared to barium should an abdominal incision to remove the contrast be necessary.

Radiographic views

Assume that the x-ray tube is moving above the table and the x-ray film is moving below the table (overcouch):^[1] The subject lying supine to give AP (anteroposterior) view of all the bowels.^[1] Left lateral view of rectum is to view the rectum from lateral position.^[1] Right anterior oblique (RAO) position is to view the caecum, ascending colon, right hepatic flexure and sigmoid colon without overlapping of other bowels.^[1] Left anterior oblique (LAO) position is to view the splenic flexure without overlapping of other bowels.^[1] Left posterior oblique (LPO) position is to view the sigmoid colon without overlapping of other bowels.^[1] Hampton's view (prone caudal view) of rectosigmoid colon is taken when the subject is in prone position with the X-ray tube tilted towards the feet at 30 degrees. This is to separate out the loops of sigmoid colon.^[2]

Other views include right and left decubitus views^[1]

Risks

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 ultrasounds 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.

Related Research Articles

Gastroenterology is the branch of medicine focused on the digestive system and its disorders. The digestive system consists of the gastrointestinal tract, sometimes referred to as the GI tract, which includes the esophagus, stomach, small intestine and large intestine as well as the accessory organs of digestion which include the pancreas, gallbladder, and liver.

Colonoscopy or coloscopy is a medical procedure involving the endoscopic examination of the large bowel (colon) and the distal portion of the small bowel. This examination is performed using either a CCD camera or a fiber optic camera, which is mounted on a flexible tube and passed through the anus.

An upper gastrointestinal series, also called a barium swallow, barium study, or barium meal, is a series of radiographs used to examine the gastrointestinal tract for abnormalities. A contrast medium, usually a radiocontrast agent such as barium sulfate mixed with water, is ingested or instilled into the gastrointestinal tract, and X-rays are used to create radiographs of the regions of interest. The barium enhances the visibility of the relevant parts of the gastrointestinal tract by coating the inside wall of the tract and appearing white on the film. This in combination with other plain radiographs allows for the imaging of parts of the upper gastrointestinal tract such as the pharynx, larynx, esophagus, stomach, and small intestine such that the inside wall lining, size, shape, contour, and patency are visible to the examiner. With fluoroscopy, it is also possible to visualize the functional movement of examined organs such as swallowing, peristalsis, or sphincter closure. Depending on the organs to be examined, barium radiographs can be classified into "barium swallow", "barium meal", "barium follow-through", and "enteroclysis". To further enhance the quality of images, air or gas is sometimes introduced into the gastrointestinal tract in addition to barium, and this procedure is called double-contrast imaging. In this case the gas is referred to as the negative contrast medium. Traditionally the images produced with barium contrast are made with plain-film radiography, but computed tomography is also used in combination with barium contrast, in which case the procedure is called "CT enterography".

A rectal prolapse occurs when walls of the rectum have prolapsed to such a degree that they protrude out of the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depending on whether the prolapsed section is visible externally, and whether the full or only partial thickness of the rectal wall is involved.

Diverticulosis is the condition of having multiple pouches (diverticula) in the colon that are not inflamed. These are outpockets of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. Diverticula do not cause symptoms in most people. Diverticular disease occurs when diverticula become clinically inflamed, a condition known as diverticulitis.

Radiocontrast agents are substances used to enhance the visibility of internal structures in X-ray-based imaging techniques such as computed tomography, projectional radiography, and fluoroscopy. Radiocontrast agents are typically iodine, or more rarely barium sulfate. The contrast agents absorb external X-rays, resulting in decreased exposure on the X-ray detector. This is different from radiopharmaceuticals used in nuclear medicine which emit radiation.

Gastrointestinal diseases refer to diseases involving the gastrointestinal tract, namely the esophagus, stomach, small intestine, large intestine and rectum, and the accessory organs of digestion, the liver, gallbladder, and pancreas.

Virtual colonoscopy is the use of CT scanning or magnetic resonance imaging (MRI) to produce two- and three-dimensional images of the colon, from the lowest part, the rectum, to the lower end of the small intestine, and to display the images on an electronic display device. The procedure is used to screen for colon cancer and polyps, and may detect diverticulosis. A virtual colonoscopy can provide 3D reconstructed endoluminal views of the bowel. VC provides a secondary benefit of revealing diseases or abnormalities outside the colon.

<span class="mw-page-title-main">Volvulus</span> Twisting of part of the intestine, causing a bowel obstruction

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Lower gastrointestinal bleeding, commonly abbreviated LGIB, is any form of gastrointestinal bleeding in the lower gastrointestinal tract. LGIB is a common reason for seeking medical attention at a hospital's emergency department. LGIB accounts for 30–40% of all gastrointestinal bleeding and is less common than upper gastrointestinal bleeding (UGIB). It is estimated that UGIB accounts for 100–200 per 100,000 cases versus 20–27 per 100,000 cases for LGIB. Approximately 85% of lower gastrointestinal bleeding involves the colon, 10% are from bleeds that are actually upper gastrointestinal bleeds, and 3–5% involve the small intestine.

Ischemic colitis is a medical condition in which inflammation and injury of the large intestine result from inadequate blood supply. Although uncommon in the general population, ischemic colitis occurs with greater frequency in the elderly, and is the most common form of bowel ischemia. Causes of the reduced blood flow can include changes in the systemic circulation or local factors such as constriction of blood vessels or a blood clot. In most cases, no specific cause can be identified.

Bisacodyl (INN) is an organic compound that is used as a stimulant laxative drug. It works directly on the colon to produce a bowel movement. It is typically prescribed for relief of episodic and chronic constipation and for the management of neurogenic bowel dysfunction, as well as part of bowel preparation before medical examinations, such as for a colonoscopy.

Whole bowel irrigation (WBI) is a medical process involving the rapid administration of large volumes of an osmotically balanced macrogol solution, either orally or via a nasogastric tube, to flush out the entire gastrointestinal tract.

Stercoral ulcer is an ulcer of the colon due to pressure and irritation resulting from severe, prolonged constipation due to a large bowel obstruction, damage to the autonomic nervous system, or stercoral colitis. It is most commonly located in the sigmoid colon and rectum. Prolonged constipation leads to production of fecaliths, leading to possible progression into a fecaloma. These hard lumps irritate the rectum and lead to the formation of these ulcers. It results in fresh bleeding per rectum. These ulcers may be seen on imaging, such as a CT scan but are more commonly identified using endoscopy, usually a colonoscopy. Treatment modalities can include both surgical and non-surgical techniques.

An abdominal x-ray is an x-ray of the abdomen. It is sometimes abbreviated to AXR, or KUB.

A double-contrast barium enema is a form of contrast radiography in which x-rays of the colon and rectum are taken using two forms of contrast to make the structures easier to see. A liquid containing barium is put into the rectum. Barium outlines the colon and rectum on an x-ray and helps show abnormalities. Air is also put into the rectum and colon to further enhance the x-ray.

The rectum is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. The adult human rectum is about 12 centimetres (4.7 in) long, and begins at the rectosigmoid junction at the level of the third sacral vertebra or the sacral promontory depending upon what definition is used. Its diameter is similar to that of the sigmoid colon at its commencement, but it is dilated near its termination, forming the rectal ampulla. It terminates at the level of the anorectal ring or the dentate line, again depending upon which definition is used. In humans, the rectum is followed by the anal canal, which is about 4 centimetres (1.6 in) long, before the gastrointestinal tract terminates at the anal verge. The word rectum comes from the Latin rectumintestinum, meaning straight intestine.

Colonic ulcer can occur at any age, in children however they are rare. Most common symptoms are abdominal pain and hematochezia.

References

1 2 3 4 5 6 7 8 9 10 11 12 Watson N, Jones H (2018). Chapman and Nakielny's Guide to Radiological Procedures. Elsevier. pp. 60–63. ISBN 9780702071669.
↑ Elizabeth, MU; Campling, Jo; Royle, AJ (9 November 2013). Radiographic Techniques and Image Evaluation. Springer. pp. 306–307. ISBN 9781489929976 . Retrieved 27 November 2021.

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

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[Chapman_2018-1] 1 2 3 4 5 6 7 8 9 10 11 12 Watson N, Jones H (2018). Chapman and Nakielny's Guide to Radiological Procedures. Elsevier. pp. 60–63. ISBN 9780702071669.

[2] Elizabeth, MU; Campling, Jo; Royle, AJ (9 November 2013). Radiographic Techniques and Image Evaluation. Springer. pp. 306–307. ISBN 9781489929976 . Retrieved 27 November 2021.

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