I have a lump btwn my vulva and anus, its a Lil painful. Had it before and I was looking at the causes such as cancer spreading, contaminated stool, fluids leaking after child birth, poor hygiene, and aids. I don t think I have cancer, I just had a negative HIV test in June and back in November, I ve never had a child, I wash myself pretty good, and I don tthink my dstool is contaminated. and it mentioned a depresses immune system. I have been under the fan at night and I m catching a cold but I don t think that s the cause either. What can it be?