What was found
CREW REPORTED AIRCRAFT BEGAN TO FILL WITH SMOKE AND A SMOKE TOILET CAS MESSAGE ON TAKEOFF ROLL ON DEPARTURE FROM CLT. CREW FOLLOWED QRH, RETURNED TO CLT AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED, REMOVED AND REPLACED COALESCER BAGS ON LEFT AND RIGHT ACM WATER SEPARATORS, REMOVED AND REPLACED LAVATORY SMOKE DETECTOR AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. NO SMOKE OR SMOKE TOILET MESSAGE OCCURRED DURING MAINTENANCE CHECKS. AIRCRAFT RELEASED FOR SERVICE.