The word "compassion" actually comes from several different Greek words:
1. Racham: to love, pity, be merciful
2. Chamal: to pity, spare
3. Sumpatheo: to suffer with (another)
8. Splanchna: to have the bowels yearning
Basically, it implies that someone is so "moved" (har har) feeling sympathy for someone else, that it's "gut wrenching" or it makes one sick to their stomach with emotion. It makes sense, right?
And in case anyone was wondering, while we're on this topic, how English got the word "compassion" from all that, it came from the Latin words with the same meaning as the Greek:
Com (with) + Pati (suffering)
I know I'll think about compassion and my digestive system a little differently now!