I rent a house... the toilet is old over 20 yrs is say. It flushes in a swirling motion, and is very sluggish. Liquids flush fine, but paper, tampons and sometimes poop residue comes back and it will look as if the toilet is going to back up before it flushes. Liquids only don't do it. Will a new toilet/tank fix this or is it something else,possibly?

You have blockage in sewer line. Try snaking from toilet to clear it. If this does not work will have to snake down from roof vent.Go at lest 10 feet past toilet height.

Should not be flushing tampons. This could be your problem. They could be causing the blockage.

Chuck

I have one that most repair plumbers miss.. Look down at the bottom of the bowl. If there is a small hole, then that is a jet that starts the syphon action. If it's clogged the water will just swirl around and slowly go down leaving solids behind. Take your finger,(UGH! ) and run it around the inside of the opening. Over the years minerals build up and cut down on the syphon (flush) action. If it is rough or you feel build up, take a table knife and put a bend in it to get around the curve in the bowl and chip and scrap it clear. Next take a coathanger and clear out the holes around the rim. They start the swirling action. And last, check the water level in the tank. It should be 1/2" below the top of the over flow tube. And speaking of the overflow tube, Make sure the small 1/8" tube from the ballcock to the white overflow tube is connected so it discharges in it and that it's flowing when the ballcock fills. This is what raises the water level in the bowl. For a good solid flush they all have to work together. Hope this helps. Good luck, Tom

Ha... show me a woman who doesn't flush tampons!!

Ha... show me a woman who doesn't flush tampons!! ]
And I'll show you a woman with less plumbing bills then one who does.
Cheers, Tom