You feel terrible for the children? 
No really, thanks but no thanks.
We dont need pity. Understanding and respect yes, you feeling bad for our kids, not so much.
Listen to what the parents are telling you. Try and at least understand a tiny bit of what our children go through.
My friend took her little girl to hospital a few weeks ago. They kept her waiting, NIL by mouth for 5 hours. She had to sit in an empty room with no tv, no toys, no company for all that time.
Then she was given sedation that didnt work. Then she had to have a series of very, very painful injections that caused her to scream and writhe so much she had to be held down.
All the time being told 'come on now its not that bad'.
She has to go back and do that again in a few months. She is 7. That is her LIFE.
Her mother was trying to tell the doctors that the sedation hadnt worked, that it doesnt work for her DD, the child was telling them that it hadnt worked.
This is just one incident in one child's life. I wont go into some of the stuff that happened to my DD. Its too distressing.