What Causes Bleeding After Sex Along With Constipation?

I am a 47 year old female who has had problems on/off with my menstrual cycle. In Feb. 2010 I had a surgery to help minimize bleeding. Lately after everytime I have intercourse I statrt to bleed and I don't stop it seems like until after my period starts and ends. I have become very gassy and constipated. Should I be concerned?