As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RECEIVED "SMOKE TOILET" MASTER CAUTION THROUGH 5K. MESSAGE CLEARED AFTER 2 MIN. RETURNED TO ORD. NO EVIDENCE OF SMOKE OR ODOR DETECTED IN THE CABIN OR COCKPIT. O2 MASKS NOT USED. ***AIRCRAFT REMOVED FROM SERVICE***** R&R LAV SMOKE DETECTOR PER CRJ 200 AMM 26-16-01 OPS CHECK GOOD. R&R BOTH COALESCE SOCKS PER CRJ 200 AMM 21-51-13/ CLEARED AIR SUPPLY DUCTS PER AWAC SUP 09-037D NO SMOKE OR ODER DETECTED AT THIS TIME SN OFF 10722 S/N ON 07994