My first thought about the images was long strings of blood in mucus. They do seem to have a definite shape so maybe they are the shape of ruptured blood vessels in the lower intestine. I have seen samples from amoebic dysentery with blood and mucus. There is a parasite Protozoa forum where you can ask about the various intestinal protozoa which produce blood and mucus in the stool.
Then I thought of the schistosomes which live in the intestinal blood vessels so searched for 'schistosoma adult feces images' so you can look at those.
If flukes are the bile system they may not come out after treatment, I have only seen flukes from the bile system after using herbs and doing a LF.