What type of contrast media is use in Upper gastrointestinal series?

In upper gastrointestinal (GI) series, a type of contrast medium called positive contrast agents is used. Positive contrast agents are substances that appear white on X-rays and are taken orally by the patient. These agents coat the inner lining of the upper GI tract, including the esophagus, stomach, and duodenum, and help to highlight any abnormalities or lesions that may be present. Common positive contrast agents used in upper GI series include barium sulfate suspension and water-soluble contrast agents such as diatrizoate meglumine and iohexol. These contrast agents are generally safe and well-tolerated, however, some patients may experience side effects such as nausea, vomiting, or constipation.