Food dye is indestructible.
Of recent times I've been clearing out my house and workspaces of old things I will likely never use- old metal things I will never weld into anything, odd chunks of glass I don't immediately need, neon tubing that I don't have the time to work on... loads of stuff has gone to the landfill.

It's hot, sweaty work, and after a recent load I stopped at the gas station for a drink. Gatorade was on sale, so I got two bottles of electric blue sugar water with electrolytes. I drained them before I got back to the house.

The next morning as I went through my usual morning routine, I discovered that food dye does not break down in the digestion process.

I had shat out an entire clan of Smurfs.
( The Resident Loon Not a demographic. Do not measure., Tue 14 Aug 2012, 20:15, 3 replies)

Guinness has the exact same effect
except it's a clan of ninjas.
(ParaSitius is an Optimistic Pessimist, Wed 15 Aug 2012, 9:30, closed)

With or without the little white hats?

( shinyshinyscalp less a man, more a way of life, Wed 15 Aug 2012, 14:09, closed)

Without.
Although it did occur to me that had I eaten beets that night I would have shat out Nac Mac Feegles. (Yes, I've been reading Pratchett again.)
( The Resident Loon Not a demographic. Do not measure., Wed 15 Aug 2012, 14:36, closed)