In some cases, a CT can still provide valuable information without the administration of a contrast agent, and the physician may decide this is the best course for the patient at risk of reaction to contrast. The information contained herein is only a general guideline. Oral contrast is often used to enhance CT images of the abdomen and pelvis. There are two different types of substances used for oral CT contrast. The second type of contrast agent is sometimes used as a substitute for barium and is called Gastrografin.
Barium contrast looks like and has a similar consistency as a milk shake.
Gastrografin contrast is a water-based drink mixed with iodine and has a tinted yellow color. When given orally, gastrografin may taste bitter. The oral contrast is swallowed and travels into the stomach and then into gastrointestinal tract. It is important to eliminate as much food as possible from the stomach and intestines in order to help the sensitivity of the CT exam using oral contrast. Food and food remains can mimic disease when the oral contrast is present.