I have a finished basement with a full bathroom and there is a strong sewer odor coming from it.any suggestions?

i have a finished basement with a full bathroom and there is a strong sewer odor coming from it.any suggestions?

Check the water in the floor drain trap. Where's the smell the worst? Toilet, sink or tub/shower? Regards, tom

Thanks anyway,tom.I used bleach in the toilets both up and downstaris as well as in the sinks which seems to have cured the problem,which I am guessing was soap scum and hair deposits.