Omnipaque (iohexol) is a nonionic, low-osmolar contrast agent and is also available for oral use, offering gastrointestinal (GI) visualization with minimal side effects. Omnipaque has a neutral taste that even kids will drink.
Orally administered iohexol is poorly absorbed from the normal gastrointestinal tract. Omnipaque is well tolerated and absorbed if leakage into the peritoneal cavity occurs.
The recommended dosage of undiluted Omnipaque (at a concentration of for example 350 mg/mL) for computed tomography of the abdomen in adults is 500 mL to 1000 mL, diluted to concentrations of 6 mg/mL to 9 mg/mL. The oral dose should be administered about 20 to 40 minutes prior to the CT scan.

Reno-60® is radiopaque contrast agent with a wide range of indications. Reno-60 should be at body temperature when injected and may need to be warmed before use. Following intravascular injection, iodinated contrast materials are transported through the bloodstream to the kidneys and excreted by glomerular filtration.

Tomocat® is a concentrated strawberry flavored barium sulfate suspension. Tomocat® can be used as an oral or rectal (colon) contrast medium for computed tomography of the gastrointestinal tract. The quantity and the barium sulfate concentration will depend upon examination, used technique, clinical needs and patient size.

VoLumen® is a low density barium sulfate contrast agent especially designed for MDCT (multi-detector row CT) and PET/CT exams to mark the bowel. Volumen is useful for CT studies of the small bowel and mesenteric vessels.
Positive oral contrast media may limit the delineation between soft bowel tissues and the lumen and may cause artifacts. Water or methyl-cellulose transits very rapidly and may limit bowel distention and soft tissue differentiation. Volumen, similar to water appears hypodense (low Hounsfield values) on CT scan and can be used in conjunction with IV contrast. VoLumen's low density formulation is well-suited for computed tomography enterography.

Barium sulfate (BaSO4) is an inert and insoluble white powder with high density. Barium belongs chemically to the group of heavy metals. Mixed with water and additional ingredients (e.g., sweetening agents), barium sulfate is the preferred positive contrast agent for abdominal x-ray and computed tomography examinations. The extremely low solubility of barium sulfate protects patients from absorbing harmful amounts of the metal (water soluble metal compounds are often highly toxic). The high density in x-ray examinations is related to the high atomic number, since large nuclei absorb x-rays much better than smaller nuclei.
Barium sulfate agents for opacification of the gastrointestinal tract are not absorbed or metabolized and are resistant to dilution. These contrast agents are opaque white suspensions and usually swallowed or administered as an enema. They provide better delineation of mucosal details and are less expensive than water-soluble iodinated contrast media. The elimination rate is a function of gastrointestinal transit time. After GI application, it leaves the body with the feces.

Contraindications of barium sulfate products in case of known or suspected: