If you often notice waste being left in your toilet after you flush, there could be an issue with your system. Before you buy a replacement, there might be a problem that is relatively easy to fix. Here are some of the most common issues and how to fix them:
Clogs: An easy way to check if something is clogging your system is by pouring a gallon of water into the bowl. Flush it and, if it drains slowly, you might be dealing with a partial clog. You can use a plunger or a snake, but there are some other methods to unclog a toilet without a plunger.
Vinegar soak: To use this method, you need to open the lid to the tank and remove the fill hose. Place a funnel into the overflow tube and pour in four cups of white vinegar. Leave it for a couple of hours, then put everything back into place and flush the toilet. The acidity in vinegar effectively breaks down grime and clogs (source).
Clogged rims: The water that comes from the toilet’s rim helps to keep the bowl clean. However, these rims can also become clogged. When cleaning your toilet, run the brush along the inside of the rim to remove any possible blockages (source).
Replacing a pipe: If none of the previous methods work, you will need to make some more drastic changes. Pipes that are too small for your toilet are a common cause of blockages and they might need replacing or upgrading. Unless you are an experienced plumber, this is a task that is best left to a professional.