My three of my dogs all go CRAZY for popcorn. We have it every Friday when the family watches movies, and we have the most violent fights between the Basenjis over it. Most of the time, since Keoki moved in, those two dogs have to go outside for a while so the kids can enjoy their movie/popcorn w/out dealing with the dogs. We always make sure there is a lot left for the dogs, though.
For the record, none of the dogs ever show any bowel side effects from the popcorn gorge.