Can I get advice? I've got all a type of leukemia. How painful is a bone marrow transplant?

Marrow transplant. Chemotherapy is given first, to try to wipeout as much leukemia as possible from your marrow, then as it is recovering from the chemo, the marrow is infused into your body through the veins, to help you recover faster. Other than the needlestick, there should be very little pain.