As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 1072 EN ROUTE. ON GROUND, WITH APU RUNNING, A "STRONG" URINE TYPE SMELL ON AIRCRAFT, MID CABIN TO AFT. ODOR LESSENED WITH ENGINES RUNNING. IN-FLIGHT, PAX AND F/A COMPLAINED. MAINTENANCE REPLACED LEAKING LAV DRAIN LINE ATTACHMENT FITTING. NO LEAKS NOTED. OPS CHECK NORMAL.