While I was in the shower, the water from the toilet drained and came out of the shower head.

While I was in the shower, the water from the toilet drained and came out of the shower head.
That is just not possible.

Perhaps you mean it came up the drain.

You would need to have some negative pressures in the system, highly unlikely. Please explain exactly what happened.

No worries, this happens all the time. All you need to do is call a licensed plumber and you will get things all fixed up. Or, you can trust us to give you free info and hope that we are telling the truth, or more accurately, know what we are talking about. Good luck.