When I was 6 or 7, there were these videos I used to rent called THE MAGIC SCHOOL BUS. It was about a school bus that could shrink and do other things so the students could go on whimsical field trips. There was on episode where the bus got trapped on this one kid's food and was digested. The bus went through all the major organs and eventually got sneezed out. The idea of being digested by a classmate scared the crap out of me, and several other segments of the episode were freaky, such as the bus almost getting destroyed by the stomach acid. I found the whole episode on youtube and it isn't as scary as I remembered it being. I have posted the links below for anyone who wants to waste 20 minutes watching a bad children's show.
My 7 year old son has a love/hate thing going with the Magic School Bus show right now. He keeps insisting on renting the damn things, then watches them and says he's freaked out. They are truly awful, too, at least in terms of quality of the animation and cringe-inducing dialogue. Little Richard's rendition of the MSB theme is wretched, too. "Navigate a nostril!"