As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW ELECTED TO TURN BACK AFTER TAKEOFF DUE TO BOTH AFT LAVATORY SMOKE DETECTORS SOUNDING AND PASSENGERS REPORT AN ODOR. MAINTENANCE INSPECTED BOTH ENGINES INLETS AND EXHAUST BUT FOUND NO DISCREPANCIES. NO TROUBLE WAS FOUND AND A DUCT BURNOUT WAS PERFORMED. ACFT HAS RETURNED TO SERVICE.