Centered that takes me back to the digestive track. I would say if this thing doesn't pass/poop. A Vet. visit may be the best way to get a handle on this potential problem. From your description it doesn't sound normal. By the time a food mass has gone that far in the system it should be reduced to feces and urates. As a rule you can't see a mass or bulge.
Even some of my large garters who eat adult mice don't get a mass after it passes through the digestive track.
What kind of substrate are you using? Is it possible the snake ingested something from the enclosure?