What Causes Incomplete Bowel Movements And Pain In The Rectum?

I have had a great problem with incomplete bowel movements ,,very difficuolt to initiate take a long time ,,to pass stool ,, I went to several rectal doctors and they all told me to take stools softeners ,,,,,but they don t works well ,,,,,As some point ,I fails to complete the bowel movement and ,it feels like my rectum gets very inflamed ,,,,This leave me a a certain amount of pain ,all day ,,,, The doctors do not seem to understand that I get inflamed ,at a certain point during defication ,, its been going on for 3 yearw I take colace ,,metamucil ,,,senna ,,and I currently have tried lincess which works but it casue diarhea ,,and at a certain pint evey with the lincess I get stuck ,,and can;t complete the bowel movement Nothing seems to work ,,,