Ever since I have lived in my house the master bath toilet has never worked very well, (easily clogs, slow flow/flush action, etc) After several years of this I went into basement to check out pipes and notice that the initial downpipe from toilet flow to a pipe that slopes well for about 5 feet then turns 90 degrees and then has a upslope for about 2-3 feet. (Checked with 3' level) Could the upslope be the cause of the disfunctional toilet? If so, should I have a plumber re-install the line?