Hi,
My house was built in the 50"s. Had new sewer line put in about 10 years ago. Flush the toilet and a big bubble of air comes up and not everything flushes. Having a bath and letting the water out the sink will gurgle. Someone snaked my toilet and all is okay with this. Wonder if it could be the venting? Any suggestions.

You should snake the vents. It sounds like you have a vent line plugged in that bathroom group.

Thanks very much for responding so quickly. I will let you know. Have someone coming over today to see what it could be.