How can I get rid of this???

I can't say how to get rid of the barium, except to cause yourself to poop. If laxatives and enemas aren't working, then you need to go to a hospital and get them to clear out your impaction. But the barium shouldn't hurt you. My stepfather is a retired nuclear medicine technician and I asked him about the radioactive stuff they used in people and he said that all of it had a very short half life. Radioactive materials decay at a known rate and a material's half life is how long it takes it for it to be half decayed; so something with a half life of 1 day is only half as radioactive 24 hours after its creation and only 1/4 as radioactive 48 hous later, etc. Most of the stuff they use ceases to count as radioactive within 24 hours, 48 at most. And of course, it's not highly radioactive in the first place.