Does pelvic floor myalgia make your back hurt? Constantly? ?

Can someone please tell me what pelvic floor is and if it affects your back. And anything else please? My back has been hurting for a couple years off and on. And now it's just constant. And I want an idea of what it could be. My tailbone is pushed up. And occasionaly I have bleeding out of my rectum(minimal). Please get back to me as soon as possible. Thanks