There’s a test invented in Israel where you swallow a capsule with a camera in it. It takes photos all the way through the system and comes out at the end. That’s technology!
From experience, in order for that camera to work one would still have to clean the colon basically not eating all day and then drink the horrible lemon flavored mix that you must keep drinking glass after glass while running to the toilet to poo a stream till no solids are left.
I’ll go with the poo sample thank you very much.
Used to doing like that anyway with the pick-up dog poop law.