anesthesia
"Was given propofol for colonoscopy.  As soon as the nurse gave it to me, my arm started burning like it was being dipped in acid.  Unbelievably painful. I sat up and reached to pull the IV out of my arm and then the drug took effect and I lost consciousness.  It is was a barbaric, excruciating experience that thankfully was over quickly.  Should have at least warned me that it would hurt."