The animation for the Pop Rocks story was changed
completely before the episode went to air. In the original,
Colin peeks out the door first, squirms a little, then comes
out of the house. For the entire time, he is holding his
crotch, apparently having a potty emergency of his own.
It's probably a good bet to say that the censors didn't like
that particular gag. The new animation has no gag to it.
Colin just comes out, tells the story, then goes back in.
Whether this animation was made specifically as a replacement
for this story, or whether it came from another story
entirely, has not been determined.
Once I get video capture capability, I should be able
to provide screenshots and perhaps motion video of the
original animation.