I had umbilical hernia surgery on oct 15 2012. i am having constant discharge of blood with a foul smell ever since then. dr. says this is normal ?

No: Although some patients may have some initial bloody discharge, persistent drainage should be investigated, particularly if foul smelling. Your surgeon should re-examine you in the office.

Not normal: Sound like an infected collection of blood under the skin, called a hematoma. Usually the treatment is to open the wound an let it heal by itself from the bottom up. If there is mesh placed on top of the abdominal wall, this may be ok to leave alone, or could require removal. See you surgeon for an exam again. If you are still skeptical, see your primary care.