Step 1: Building the Toilet
Set 9 blocks in a cube and break the center so you have a doughnut hole. Use your block of choice.
Step 2: The Water and Door
Put a bucket of water inside the doughnut hole. Then put one block on any side of the water hole and make sure it's one block above the others. Next add a trap door and place it right above the water hole by tapping the block that was above the others.
Step 3: Finished
Hope this minecraft toilet is useful to you and helps your bathroom problems:) You can add additional blocks to the back of the toilet.