I have noticed the quality of feed that goes in has a great deal to do with the smell when it comes out. When I get snakes in from other breeders that have not been here long yet, their defecation usually smells a bit differently than all of my snakes. I don't mean to say I have the highest quality of feeders, although I like to think they're pretty damn good since I raise them myself and give them tons of love/good food. For a while after I got my het pied pair in their defecation was runny and also smelled bad. I got them both on rats as soon as they arrived here as I have done with all my other snakes and their poop is solid now.

I'm not saying don't take your snake to get a check up if you feel it needs one, but I would not wait to get them on to rats if I can help it. I feel rats provide a lot more fat and nutrition that helps out in younger/older snakes. My butter enchi male I just got in on Tuesday took his first rat meal in his life for me on Friday, with no hesitation at all. Has yet to defecate since I have had him but I will be keeping a nose and eye out for any differences.