I Have Been Having Night Sweats, Fever And Chills. I

I have been having night sweats, fever and chills. I also have lost a lot of weight without trying. I have a purple rash above my ankle that I have had since May. I'm very tired and weak and have had diarrhea for over a year, to the point of almost having accidents everyday. When I was young my doctor said I had a spastic colon. My 48 year old sister just died of colon cancer last April. What do I need to do. My doctor ran blood tests that showed I have a 2.9 white blood cell count and a sed rate of 25.