I Have A Special Needs 13 Yo Who Had A

I have a special needs 13 yo who had a barium study 6 weeks ago. The barium is still in her large intestine. How do we get the rest out? Do we need to be concerned about it becoming hard and tearing her intestines? Is it painful? We know she has a slow moving gut, g tube fed, tried go easy 2x, and extra miralax quite a few times. Some barium remains. Please help! Any suggestions are greatly appreciated!