As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 3201 - LGA-RDU - ON CLIMB-OUT, RECEIVED "LAV SMOKE" INDICATIONS AND STRANGE ODOR. FLIGHT ATTENDANT SAW SMOKE AT ROWS 10 AND 11. RETURNED TO FIELD. RAN QRH, INDICATIONS WENT AWAY ON DESCENT TO LANDING. NO OTHER SIGNS NOTED. MAINTENANCE FERRIED TO IND. REMOVED AND REPLACED RIGHT HAND ENGINE AND PERFORMED ENGINE RUNS IAW EI001234. NO EICAS MESSAGE OR DEFECTS NOTED.