My sister in law has only 1 kidney working at about 30-40% and she is expected to need dialysis in the future. She also has an unmedicated but monitored goitre . Among her medication are the drugs Furosemide for water retention and Risperidone for Psychosis . She is due to have a CT Scan soon and has been given both Gastrografin and Picolax to take ready for the procedure. She has learning difficulties and family have to take care of her medical requirements/appointments. No advice has been given as to whether she should have stopped the Furosemide and her renal condition doesn t seem to have been taken into consideration. We have researched the Gastrografin and Picolax and there seems to be a very high risk that these may cause additional renal failure and the possibility of dialysis being needed after the procedure. What is your advise as to the safety of this procedure and the medication required to perform it given her medical history.