Leak Check

Does anyone know a way to check the drain lines in a home to see if they are leaking. The home is sitting on a slab.

Why do you want to do this? When was the house built?

During the foundation being lifed the company told me a pipe broke. They ran a camera through but did not see a crack. I can flush toilets, run sinks and showers and watch it through the clean out and the water is clean. There is no standing water or smell. The work was done over a month ago wouldn't there be evidence.