Anything white is most likely to be yeast (unless it is flatworm) . Yeast can take many forms in stool:
Snowflakes: it looks pretty much like a bunch of teared up toilet paper.
Thread: candida is normal in our body, what we are fighting is rhizomic candida: the yeast forms in long chain (rhizome) and drills into the intestinal walls.
This are the most common
But I also saw
Bulbs: round shape floating white stuff (usually I would get those after a pectin intake (green apple)
Net: Sometimes the threads would form a net, woven into one another in a proper square shape
Veil: Sometimes it would come out as a transludic veil, my guess is that the net then forms into a fabric.