Suggest Treatment For Pain From Vagina To Anus During Periods

After I got operated (cholelithiasis) last May 2009, every time I have menstruation period I am experiencing pain in my my vagina then to my anus, I can feel that there’s inflammation inside my anus then after the 3 to 5 days of pain then it subside and itchy feelings in. It really bothers me; I can’t do my normal routine. I consulted many times to doctors, ob-gynecologist, surgeon, internal med, the findings is just hemorrhoids, I got operated last October 2010. But then again the feeling is still the same during my menstruation. What can I do? I hope you can help me find ways to cure this thing.