Sewer smell in bathroom. Went in attic and vent pipe looks OK. P-traps full of water. Sometimes looks like someone forgot to flush.

Can you sniff around the drains and get a stronger smell? Is the smell stronger near the base of the toilet bowl? Where is the smell the strongest? Back to you, Tom

I'd check to see if the smell is at base of toilet. Bad wax ring is possible.

To speed things along you can also take a baseball sized ball of plumbers putty or modeling clay. Roll it into a rope aboiut 3' long and use it to tempoarily seal the base of the toilet to the floor. If the smell disappears after an hour or so you can bet on the wax ring. Do not just leave the clay in place, it is not a solution