CT Scan with IV Contrast given by an Enema into anus.

Hi, I read online: "Rectal CT Contrast" it says, "After the exam is complete, the rectal contrast will be drained and the patient may go to the bathroom."

For my CT Scan in India, I had IV contrast (with water I think) put into my anus through an enema. However I was not told to prepare for this by fasting, so I almost vomited.

What is meant by, "the rectal contrast will be drained?" What happens here and how is it drained? Once my CT scan was over, I went straight to the toilet. I had no draining process, is this ok?
 
Is it normal to have the IV contrast giving by an enema into the anus?

x

Just to know, if it is drained with the help of a doctor, what happens? Does the doctor (or nurse) hold a bucket or something? Or do they drain it out with some special device?

Also, one more thing. Is it normal to use a sterilized enema on a person? My one seemed old and brownish, so I asked the doctor (after the scan) if it was new. He said it was not new, but it was sterilized.

Can someone catch cancer, from a re-used sterlized enema?

Can someone also catch cancer, from a re-used unsterlized enema? (I know STI's can be caught, but can cancer?)

Sorry to bother lol, I've pretty much asked everything I had to, lol.