I have also had problems in the past with excessive bleeding after surgery
(2 occasions), and gums that bleed during a normal dental cleaning. I have researched this extensively, and the only thing I can find is that it may be Von Willebrand's disease. It's a common blood disorder that causes easy bruising (fragile capillaries) due to a defect in the platelets. (platelet count is normal, but clotting ability is not). I am going to ask my Dr to test me for it.