HELP! We live in a ranch-style house built in 1965. In August, 2007 we replaced the wall-hung bathroom sinks with new cabinets and sink tops. We replaced the p-traps and short pipe going from the p-trap to the sewer pipe with PVC piping. The main bathroom is fine. The half-bath is not. We get the odor of sewer every time we turn the water on-it's not noticeable any other time. Every two or three weeks I have to take the p-trap and pipe off and clean out the gunk that has collected in them, which is a gelatinous substance. We put a snake down the vent stack and it seems clear. WHAT IS OUR PROBLEM?
Thank you for any help you can give us.