Somebody here with issues mainly in rectum ?

I have pelvic floor related symptoms in my rectum, mainly it is triggered by a bowel movement or ejaculation. It gets worse by sitting. I have visitied s proctologist, he thinks I have pelvic floor issues. Does somebody have similar symptoms? How fight this condition? It started more then a year ago and nobody seems to help me. Even tried physiotherapy to fix my posture, but doing core exercises just worsen my symptoms. Not the same day however, but the next day after defecation.