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X-Ray and Other Imaging Contrast Studies of the Gastrointestinal Tract


Jonathan Gotfried

, MD, Lewis Katz School of Medicine at Temple University

Reviewed/Revised Mar 2023
Topic Resources

X-Ray Contrast Studies of the Abdomen

X-ray and other imaging contrast studies visualize the entire gastrointestinal tract from pharynx to rectum and are most useful for detecting mass lesions and structural abnormalities (eg, tumors, strictures).

Single-contrast studies fill the lumen with radiopaque material, outlining the structure. Better, more detailed images are obtained from double-contrast studies, in which a small amount of high-density barium coats the mucosal surface and gas distends the organ and enhances contrast. The gas is injected by the operator in double-contrast barium enema, whereas in other studies, intrinsic gastrointestinal tract gas is adequate. In all cases, patients turn themselves to properly distribute the gas and barium. Fluoroscopy can be used to monitor the progress of the contrast material. Either video or plain films can be taken for documentation, but video is particularly useful when assessing motor disorders (eg, cricopharyngeal spasm, achalasia Achalasia Achalasia is a neurogenic esophageal motility disorder characterized by impaired esophageal peristalsis and a lack of lower esophageal sphincter relaxation during swallowing. Symptoms are slowly... read more Achalasia ).

The main contraindication to x-ray contrast studies is

  • Suspected perforation

Perforation Acute Perforation of the Gastrointestinal Tract Any part of the gastrointestinal tract may become perforated, releasing gastric or intestinal contents into the peritoneal space. Causes vary. Symptoms develop suddenly, with severe pain followed... read more Acute Perforation of the Gastrointestinal Tract is a contraindication because free barium is highly irritating to the mediastinum and peritoneum; water-soluble contrast is less irritating and may be used if perforation is possible. Older patients may have difficulty turning themselves to properly distribute the barium and intraluminal gas.

Patients having upper gastrointestinal x-ray contrast studies must have nothing by mouth (npo) after midnight. Patients having barium enema follow a clear liquid diet the day before, take an oral sodium phosphate laxative in the afternoon, and take a bisacodyl suppository in the evening. Other laxative regimens are effective.

Complications of abdominal x-ray contrast studies are rare. Perforation can occur if barium enema is done in a patient with toxic megacolon Toxic colitis Ulcerative colitis is a chronic inflammatory and ulcerative disease arising in the colonic mucosa, characterized most often by bloody diarrhea. Extraintestinal symptoms, particularly arthritis... read more Toxic colitis . Barium impaction may be prevented by postprocedure oral fluids and sometimes laxatives.

Barium enema

Small-bowel meal

A small-bowel meal is done by using fluoroscopy and provides a more detailed evaluation of the small bowel.

Shortly before the examination, the patient is given metoclopramide 20 mg orally to hasten transit of the contrast material.

Upper gastrointestinal examination

An upper gastrointestinal examination is best done as a biphasic study beginning with a double-contrast examination of the esophagus, stomach, and duodenum, followed by a single-contrast study using low-density barium.

Glucagon 0.5 mg IV can facilitate the examination by causing gastric hypotonia.


Enteroclysis (small-bowel enema) provides still better visualization of the small bowel but requires intubation of the duodenum with a flexible, balloon-tipped catheter. A barium suspension is injected, followed by a solution of methylcellulose, which functions as a double-contrast agent that enhances visualization of the small-bowel mucosa. Enteroclysis has largely been replaced by CT or MR enterography CT enterography and MR enterography X-ray and other imaging contrast studies visualize the entire gastrointestinal tract from pharynx to rectum and are most useful for detecting mass lesions and structural abnormalities (eg, tumors... read more CT enterography and MR enterography .

CT Scanning of the Abdomen

CT scanning using oral and IV contrast allows excellent visualization of both the small bowel and colon as well as of other intra-abdominal structures.

CT colonography

CT colonography (virtual colonoscopy) generates 3D and 2D images of the colon by using multidetector CT and a combination of oral contrast and gas distention of the colon. Viewing the high-resolution 3D images somewhat simulates the appearance of optical endoscopy, hence the name. Optimal CT colonography technique requires careful cleansing and distention of the colon. Residual stool causes problems similar to those encountered with barium enema because it simulates polyps or masses. Three-dimensional endoluminal images are useful to confirm the presence of a lesion and to improve diagnostic confidence.

CT enterography and MR enterography

CT enterography and CT colonography have largely supplanted standard small-bowel series, enteroclysis, and barium enema examinations.

Magnetic resonance (MR) enterography can also be used in a similar fashion to CT enterography. It is typically reserved for younger patients, especially those with inflammatory bowel disease, to reduce lifetime radiation exposure risk. MR enterography is more expensive than CT enterography.

Drugs Mentioned In This Article

Drug Name Select Trade
Alophen, Bisac-Evac , Biscolax, Corrective Laxative for Women, Correctol, Dacodyl, Doxidan, Dulcolax, Ex-Lax Ultra, Feen-A-Mint , Fematrol , Femilax, Fleet, Laxative, Reliable Gentle Laxative, Veracolate
Gimoti, Metozolv, Reglan
baqsimi, GlucaGen, Glucagon, Gvoke, Gvoke HypoPen, Gvoke PFS
Citrucel, Fiber Therapy, Murocel, Quality Choice Fiber Theraphy
Anatrast, Bar Test , Baricon, Baro Cat, Barobag, Baropaque, Baropaque AC , Barosperse, Barotrast, CAT Pak , CheeTah, Digibar 90, Digital HD, E Z Cat , E Z Disk, E Z HD, E Z Paque, Enhancer, Entero H , Entrobar, Entroease, Epi-C , Esophotrast, Exacta II , E-Z-AC, E-Z-Paste, Flo-Coat , HD-200, HD-85 , Intropaste, Liqui-Coat HD, Liquid E Z Paque , Liquid Polibar , Liquid Polibar Plus, Liquid Sol-O-Pake , Medescan, Opti Up, Polibar, Prepcat, Readi Cat, Readi Cat 2, Scan-C, Sol-O-Pake, Stomach Barium Air Contrast , Stomach Barium Single Contrast, Tomocat , Tonojug Tonopaque, Tonopaque , Top Cat, Ultra R, VoLumen
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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