This is going to sound really dumb but so far everyone ive asked, they've never had this problem.

when i fall/jump off anything 3 or more feet high theres this sharp pain between my nuts and anus to the point where i have to stop moving and just fall over. umm. yeah. wtf.

ask your doctor. or google "signs of prostrate cancer" but most of all ask your doctor, its probably nothing, but just in case, not trying to scare you, but its better to be sure. checking with your doctor will at least alleviate your concerns even if it is nothing to begin with.

From the mouth of my boyfriend the registered nurse, "That wouldn't have anything to do with prostate cancer; you can't feel prostate cancer and that is why people die from it."