Stringy Green Poop

Will had his first excretion in my care today, and I noticed something a little odd. Here are a few pictures:
http://img23.imageshack.us/img23/4757/poop2b.jpg
By foxoftherose at 2012-08-24
http://img607.imageshack.us/img607/4011/poop1.jpg
By foxoftherose at 2012-08-24
I assume that I need to take him to a vet, but I would like to know if I should take him this afternoon, this weekend, or the first of next week.
His temps are 78 and 86, his humidity averages around 50%, and he eats regularly. What's going on here?
Also, stupid me, I rinsed it out of his tub, and now it's on the driveway. Should I try to salvage it and bring it to the vet?

There's not a whole lot the vet can do if you take the snake in, but drop off whatever remnants of the poop you can get for a fecal float (or wait until his next one and bring that in). Often times transitioning to a new environment can cause some digestive distress, but imo it's a good idea to have new snakes tested for parasites anyways.