Just what you were hoping for? Thanks to axlrosen for sending this along. It's 40 feet long, 4 feet tall, and was created with the help of an actual colonoscopy. It's the Colossal colon.
It's coming to a town near you. And the point is to introduce you to how the colon works, by allowing you to move through it.
See, normally parts of you might be digested and absorbed, which is not helpful to the learning process.
Once inside, you can see things like cancer and Crohn's disease and polyps and, well, literally the whole nine yards.
Apparently you travel in the right direction and there is no sphincter model to poot you out as you leave. Pity.