The Garbage Gang is a group of six friends who live in the city dump, although only Gordy, a small rhino, is the only living one.  The others are all inanimate.  Gordy is taking a bath when he makes a bubble that pops.    He knows it’s gas, but wonders ‘why does my body make bubbles?’  Then the bubble he made shows up and explains the digestive system, along with a field trip through the system.  There are the usual poop jokes but, actually, the information about why poop is brown, where does the smell come from, the acids and enzymes, are all interesting and factual.  The comics appearance make it easier to digest.  For those kids studying the human body and nutrition, it is a good resource.