It's been a while since I had hair long enough to have to remember to worry about that sort of thing. It reminds me that my hair really does grow fairly fast. It must, for me to lose as much as I regularly do and still have any remaining on my head! or so it seems.
Bezoar appears to refer specifically to a mass found in the gastrointestinal tract. That's a word I learned from Mr. Gaiman, courtesy of Sandman, along with the more specific trichobezoar. I can't think of hairballs, be they feline or mechanically produced, without seeing that set of panels.