In the first ten inches (Duodenum) of this roller coaster tube (small intestine) there are strange juices (bile, Pancreatic Juices,) being squirted at me from strange unseen places (pancreas, liver). It is a very tight squeeze! The roller coaster continues for a long time. On the roller coaster there are fingers grabbing at me (villi) Eventually, it ends and I am in a much wider tube (large intestine).