This was a public (not school) library.

And they were children's books, written to be appropriate for children: “Larry the Farting Leprechaun,” “Gary the Goose and His Gas on the Loose,” “Freddie the Farting Snowman” and “Harvey the Heart Had Too Many Farts,” along with “My Butt Is So Noisy!” and “I Broke My Butt!”

If someone doesn't want their 5 year old to read about farts, then don't borrow the books. If someone else wants their children to enjoy reading funny books let them.