First a little background info...
My 2-year-old female has been a bit 'off' since that serious parasite issue she had last year. She's active, eating well, and generally a very healthy snake. One thing that has been consistently very strange has been her excrement. The urates she has been passing have almost a greenish tinge to them, and the poo sometimes has a greyish quality. As she seems to feel perfectly okay, I've assumed that this is just her body continuing to deal with replenishing nutrients and thus may be absorbing different things from her waste. I've noticed this started almost immediately after she was cleared of parasites; not during the almost 5-month-long period she had them. Most all of the connective tissue in her skin was broken down (she had difficulty moving because of the deterioration of the belly scutes). Since that's not something an animal would normally have to replace quickly, it makes sense that it could be taking her awhile to completely rebuild that much connective tissue. Also, the green/greyish quality of the poo gets more pronounced right before a shed. That makes me fairly confident that it is somehow related to the nutrients she needs to keep rebuilding her skin.

I've been monitoring her closely, and I don't think that's really a reason to worry right now. I wouldn't be surprised if this continued for several more months considering how severe the issue was.

Something really strange happened today though. I found a poo that looked more like something one of my frogs would pass; about an inch long, reddish color (no blood) and solid with no urates. It had a larger diameter than garter poo normally would, and also seemed to have some sort of casing around it. It was in her water dish this morning, so it's entirely possible that it had expanded overnight.
All of her other poo has been the typical color (greyish around shed time), and somewhat runny. Which is normal considering they get a lot of worms and fish. She acts like she feels fine, and came right out to greet me this morning. I checked her over and can't find anything wrong. Doesn't look like anything she passed when she had the parasites, so I don't think it's that again.

Has anyone seen anything like that before? It was just very strange... Especially that casing around it. I'm watching her closely to make sure nothing is wrong, but she seems totally fine.