Main Line Back Up & Toilet Seal

I live in an upstairs unit of a condominium complex. A few days ago we had a main line back up due to tree roots. At the time of the back up, I had flushed the toilet and water came up from the bowl and from underneath the toilet.

The blockage has been cleared, but I am wondering if the wax seal was compromised as a result of water being forced out of the bottom of the toilet.

The seal was replaced a year ago and there had been no leakage prior to the main line back up.

Thank so much for any and all replies!!

Have it replaced! It really shouldn't have come from the wax seal if it was sealed properly; especially on the 2nd floor (assuming you are top floor). If they had tree roots, One can only suspect they will grow back in a few months. If you own the condo, maybe they will replace the wax ring for free. I don't know how your HOA works but sometimes maintenance will take care of things like that.

Water will not come out from under the toilet unless the wax seal is compromised.

seal

HOW did water come out from under an "upstairs" toilet without flooding the lower levels first? AND, how did it have enough "pressure" to get up there in the first place, since water seeks its own level and does NOT flow uphill?

I'm not sure how this happened. I flushed the toilet and water came up from the bowl and underneath. At this time my downstairs neighbor said the water from my toilet did come into her bathroom from the fan vent.
I also had water coming up from the shower. My downstairs neighbor had water coming up from her shower also, but she never tried flushing her toilet.

2nd floor?

You need to pull the bowl and reset with new wax.
It has nothing to do with the main line for the second floor. Sewage would be coming up in your neighbors shower, lavs and kitchen sink before it could ever get to the second floor.