I sometimes (at least once a month) get pain in my bladder after emptying. the pain can only be relieved when i place pressure on my bladder. help?

Bladder spasm: Sometimes a bladder spasm, like a muscle cramp, occurs in the bladder after it is emptied. It may mean that you delayed urination for a while causing the bladder to stretch, then contract more strongly after emptying. Since it occurs infrequently, no treatment is indicated, but following an old urology professor's recommendation--"never pass a water fountain or bathroom without using it!"