[quote]
Mine were mostly always brown and greatly varied in length and width. But anyway.
[/quote]

The dead worms i have seen in my feces were brown too. But they didn't have a head like on the video, they had the same shape like the ascaris.

Like these :




But with a brown color.



[quote]
Doc Sutter said that the biting sensation happens when the worms let go.
[/quote]

I don't know about the tapeworm, i haven't seen one dead.
Concerning the roundworm like the ascaris, i have noticed that the itches sensations always are felt in the same areas, that's where there is a bend in the digestive tube. My theory is that the sharp head of a big Ascaris worm can cause these itches sensations when it moves and hits the wall of the digestive tube.