[grudk]

If you are talking about donating for a marrow transplant, there are multiple aspirations and it's often done under general anesthesia. If it's a single aspiration for some other purpose, not a big deal. I've had it done when I worked in a research lab (needed marrow for experiments and they paid me $50. Not bad when you are a college student in 1985). It was done under local, and the needle is pretty good sized -- similar caliber to the ink cartridge in a ball point pen. Some serious pressure to drive that sucker into the posterior iliac crest (back of the pelvic bone). The pain I would describe as 'dental-like' -- when they sucked the marrow out -- and I was sore for a few days. Probably how Tom Cruise feels after a night on the town ('power-bottom' joke for the uninitiated)