Norwegian childrens book writers, I have to say, seem to understand their target audience... Stories such as the twin set of the little boy with diarrhea who pooed from here to there, who pooed out his dinner and pooed out his friend, who pooed out things he hadn't even eaten yet; and the book from the same author following his sister who vomited on things in much the same way her brother handled the other end of the bodily spectrum.
Or perhaps an inspiring tale of becoming comfortable with yourself for who you are, as depicted in "The Elephant Who Didn't Dare to Fart".
In a slight turn from bodily functions, there is of course the highly popular "Kurt" series of books, including the one where Kurt manages to reel in a fish the size of a large house, so he and his family decide to take a quick vacation, build a shack on top of the fish, and sail it around the world (crossing from Norway to China apparently takes 2-3 days when sailing a dead fish) while eating it out from underneath them.
...it's not entirely without bodily functions, of course, because Kurt's youngest, the boy, has as a life goal to urinate in public restrooms in every country in the world. The book covers his making a lot of headway in that lofty objective.
My goodness, these sound amazing. I mean... yeah, kid-me would have absolutely freaking loved them, but I'm not ashamed to admit that I'm in-touch enough with my inner child that reading those synopses made me chuckle out loud.
Yep. There was actually another childrens book that got made into a film relatively recently; "Doctor Proctor's Farting Powder", where a couple kids meet the mad scientist living next door, and find among his many bizarre inventions a prank farting powder so powerful, that a person can fly through the air using only flatulent force.
What follows is a rousing romp of action and intrigue, as another fellow catches wind of the wind-breaking and tries to steal the formula himself so that he can patent it and get rich. Much farting, crashing into things, and traveling through toilets is involved.
"Author Jo Nesbø's daughter wanted him to write her a story about a little girl, a boy who was shorter than her, a mad scientist and a dinosaur. Nesbø changed the dinosaur into an anaconda and added the plot about the fart powder, since he always wanted to write a children's book about farting."