Today while my wife was sitting on the toilet water shot up from the toilet, not the tank and sprayed her as if she were using a bidet

Very unusual. Was another toilet some where else flushed when this happened?

Is this a single level home or what?

No, happened around 3 pm with only one person at the time in the house. It kind of freaked her out.

Is this a single level home or what?
Let me know if you did not receive another post from me please but it is a single level home

More details please! Was your problem with any other fixtures or just the one toilet?
Was the city working on the street main? Has this happened again? Can you give us more details? Back to you, Tom

More details please! Was your problem with any other fixtures or just the one toilet?
Was the city working on the street main? Has this happened again? Can you give us more details? Back to you, Tom

I have no knowledge of street main work being done, none on our street for sure. This house was built in 1951. New piping done in past two years, both input and output including new main to street. This has not happened again. Single story house with two baths. No water being used anywhere in house at the time. The toilet is a low water usage, 1.6 gal's I believe. No leaks anywhere that we are aware of.

Is it a pressure assist toilet?

Is it a pressure assist toilet?

Not a pressure assist, standard old style with no frills or changes made to toilet

Okay guys! Let's take a moment and use some logic. This situation couldn't have happened the way the OP posted. We can eliminate water from the tank because the OP says so in his first post.
So the problem had become from the main. If there were enough back pressure to shoot the water up out of the toilet bowl water would shot up out of every trap in the house. Since OP didn't complain about that I question whether it happen that way at all.
And where did all that back pressure come from in the first place? Perhaps the OP would care to clear that up for us. The ball's in your court Freewiikki. Back to you, Tom

The wife says that the water was "brown" water and that while sitting and getting her bottom "washed" the bath tub "made funny noises" She, after cleaned herself up she went straight back to bed. It still has not happened again to date. My first thought was the vent being clogged or covered with leaves. Second is that the main had a blockage that was a temporary blockage in the newly replaced main sewage line. Sorry guys that is all I have.