Barium enma test requires i drink a prep & enema 4 evacuation. but i have an ostomy bag and stoma. should i take the prep if my rectum is inactive?

Yes: The purpose of the prep is to get all of the stool out of your colon so that the walls of your colon can be seen on the x-ray. This is important as all the x-ray sees is what the barium sticks too, be it your colon or whatever is in it. If the prep isn't good enough, you'll likely have to repeat it or go in for more invasive tests.

Yes: I will say "yes" because you put out stool through your colostomy bag and therefore it needs to be removed before barium enema. The only question i really have is why would you need to have barium enema to evaluate your colon when you can have colonoscopy? When barium enema is done on people without colostomy, they are usually expected to contract their anal sphincter to hold it. What about you?