Hi, haven't had it done but am a radiographer. Most likely they will lie her on the couch give her some barium & milk (the hardest part LOL - sometimes from a bottle or else squirted into her mouth with a syringe, like you would nurofen. They will watch it go down and then you and Dr will roll her up onto each side whilst they look ro see if any refluxing back.up her oesophagus. It's simple and pain free but can be tricky getting them to take it in the firstplace. Just have plenty of wipes and a change of clothes and as others have said cool boiled.water for after as quite constipating. And don't be surprised barium is white in, white our ;o) hope it goes well. Dr should be able to say fairly quickly whether the reflux has shown, but its tricky because its only a snapshot in time, so just because it may not have shown when they're looking, doesn't mean its not there. It just helps them rule out a structural abnormality etc. Hope something in there was helpful x