Could someone help me out with this self-diagnosis? (Let me say, this is not a joke and I am being very serious) For the past two years, I believe, after each uncharacterisically large bowel movement (either one that consists of firm stools or a large movement of loose stools) either before, during, or after, I have severe internal/an-al pains that seem to pulse in my left testicle.  Now, cancer is unlikely since I am only 17-years old, but I have been considering this.  There is no blood in my stool, but I think there had been a cut in the anus a few years ago which I had the doctor examine, but he found nothing.  I must also note the other consequent symptoms and characteristics of these pains - they pulse, last for between 1-10 minutes, cause me to become very cold and have cold sweats, and feel to be internally.  It also seems that the an-us tenses along with the perineum, perhaps in a sort of an-al spasm.  Also, even without having a bowel movement, I am sometimes woken by these same pains in the middle of the night.  Please help!

Summarized question: What are possible causes of severe internal anal pains?