shroom
I will have to be careful how I comment on this one. I don't think it is anything parasitic, but it is weird. Keep in mind, you are bowel cleansing, and things loosen up. If you clean up poop, you do see all sorts of strange looking things, many look like
parasites [or our perception of them].
The bowel is a chemical factory, and can make all sorts of things, and everyone is different. I will say try and remember what you eat, and next time you consume something that could in some way look like that, it might be worth taking note.
I remember one person kept finding little rubbery things in her stool that were red, but she realized later it was the capsules from her supplements. Some bacterial produce rubbery substances, there could be a few unexpected explanations.