slow flushing toilet
It could be that the line or a vent is stopped up. But before I went through all the time and mess of pulling the commode or paying a plumber to do so, I would check the jet holes. At least if it is an older toilet. If it is visible, check the main jet at the bottom of the bowl, and also there are several smaller ones around the bottom of the rim. If the one in the bottom is clogged, it can be cleaned out with a short screw driver, a wire coat hanger, or a combination of the two. The clog will be hard as it will be mineral deposits but it will break up. The holes around the bottom of the rim are easily cleaned with a wire coat hanger.