Hello, Before Barium CT scan the treating doctor will assess the patient s medical history and determine whether barium is safe to use. In some cases, alternative contrast agents may be used. Inform your underlying health condition in detail to your doctor. People having certain medical conditions like gastrointestinal perforation, bowel obstruction, recent abdominal surgery should avoid barium ingestion due to the risk. Barium is not absorbed by the body & can cause constipation. To avoid the risk of aspiration, the person should be positioned correctly, and swallowing should be monitored during the administration of barium. Aspiration can cause complications like lung infection or pneumonia. Sometimes it may cause itching and rash. If you have allergy you are advised to give your history of allergies before administering barium. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician