I would guess it was hypertension, strictly because the others don't seem to fit.
That's the 'alimentary canal' ... the whole path that food takes
between your body's intake and waste output.
Cats can purr for various reasons, using the soft rumble as a way of communicating and as a form of self-soothing or even healing. This is why cats will often purr when they're injured, or after a stressful event.
