Many problems in the body may arise soon after the bone marrow transplant because the bone marrow wipes out by the medicine or radiation just before the transplant. Graft failure: Graft fails when the body does not accept new stem cells. The stem cells that do not go into the bone marrow and multiply like they should. Graft failure is common when the patient and donor are not well matched and when patients get stem cells that have had the T-cells removed. This may also happen to patients with lower number of stem cells such as a single umbilical cord unit but it isn’t common. Graft failure may lead to severe bleeding and infection.