This one is actually easy to diagnose, in my humble nonmedical opinion, because there isn't really any sort of open wound that can stay open for months painlessly without healing or getting infected except a granulation-type issue. A tear, an injury, to the various areas, such as for example an early injury popping a few stitches, will heal through clotting in a few days. Or if it doesn't, it'll get infected, which will make it puffy, painful, puss-filled... Of course, yeah, go to an OB/GYN.... they can burn it off using silver nitrite I believe, as it is a common problem with childbirth and vaginal surgeries apparently due to the moistness of the area....
http://www.hystersisters.com/vb2/article_157308.htm#.U3HL1vn3A2A
