As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN TO ATL DUE TO LAV FUMES IN CABIN. LEVEL AT FL290 FLT ATTENDANTS REPORT STRONG LAV FUMES THROUGHOUT CABIN. IN DESCENT FLT ATTENDANT REPORTED ODOR DISSIPATED SOMEWHAT BUT STILL STRONG IN REAR OF CABIN. FOUND LAV OVERFLOWED. CLEANED LAV AND SERVICED.