Placing A Tub/shower On A Slab

Unregistered

I have a ground level roughed in bathroom. The home is 7 years old. There is a stub for a toilet capped off and another 2" stub for a shower/tub. The shower/tub stub is extended to the joists overhead and tied back into the vent system. Is there and easy way to identify the presence of a trap under the slab?

Unregistered

the pipe you think is an old tub drain, if you cut it about 12" above the floor and shine a flash light down the pipe after pouring a glass of water in the pipe and it is holding water then it should be a trap.