I'm pretty sure it is though I've never had a regurge from either of my snakes before. I fed her at about 4pm on Wednesday (I thought the rodent looked very slightly bigger than usual though it was supposed to be a medium mouse - but no more than a couple of millimetres bigger) but it went down normally.
This morning when I got up to go to work there was this smelly thing in the corner of her viv and it was lighter than her normal poo and closer investigation (wonderful for first thing in the morning) revealed it was still definitely mouse shape and though it was just a bit more squishy than a fresh mouse would be it even had some whiskers attached and the feet. The stomach had started to disintegrate I think because there was blood there. So I'm guessing it was regurge (although I would have thought a regurge would have happened sooner - this must have happened some 36 hours after she ate it). It was no more smellier than normal snake poo.
I feed her once a week (should I feed her only once a fornight?) she has only ever once before refused a weekly feed.
(I did take a pic but it came out bad)