The other day i went to the bathroom no bleeding, laid back down got up later blood on the bed, went to the bathroom poured blood. why?

Rectal bleeding: Rectal bleeding is abnormal and must be explained. If it was bright red blood and not mixed in with the stool, it may well have been hemorrhoids that bled. Other causes would be diverticulosis of the colon, inflammatory bowel disease or growth or growths in the colon. Your physician, gastroenterologist or colorectal surgeon are best qualified to evaluate you. Any appropriate tests will be ordered.