Without altering the plumbing, it is possible to update to a modern toilet. There are various ways to swap out an old toilet for a new one without having to change the plumbing:
One-piece toilet: A one-piece toilet has a tank and bowl that are connected by a single, seamless component. As long as the rough-in dimensions (the distance from the wall to the centre of the waste outlet) are the same, these toilets can be placed in the same spot as your previous toilet.
Two-piece toilet: During installation, a two-piece toilet's separate tank and bowl are joined together. As long as the rough-in measurements are the same, these toilets can easily be put in the same spot as your previous toilet.
Upflush toilet: An upflush toilet can be installed in places where conventional plumbing cannot because it employs a pump to push waste up and out through a pipe. These toilets need access to a power source and are often more expensive than standard toilets.
Remember that while upgrading to a modern toilet is possible without moving the plumbing, you might still need to make a few minor changes to the plumbing or the surrounding area to instal the new toilet correctly. To make room for the new toilet, the wall or the floor might also need to be changed. Consult a licenced plumber if you have questions about the installation procedure.