I had an upset stomach and diarrhea for several days. So much wiping made anal area very sore and sensitive. Now I have a large knot about the size of a cadberry egg beside the anal hole. It is very red and swollen, the swelling has spread to my vagina , and it hurts to touch stand sit, move. My groin hurts in the crease of my leg almost all the way to my stomach. What could it be, and what kid of a doctor should I see?