I just realized that part of the Magic School Bus intro shows them driving through an an*s GIF

Yeah they go to the lower intestinal but they do not go through the anus. It was an episode where they went inside one of the students to show how digestion works. The kid eat his gum and the teacher was teaching them that it isn't true that it stays in you for 7 yrs or whatever.
Honestly it was a good episode but of course all the episodes are good.

Imaging going to a field trip you are so excited for just to realize you're in an anus