Damage
Water damage can occur from flooding in your bathroom. If you have vinyl flooring, it can be soaked, as can wooden vanities. Water can seep underneath the vinyl and damage wooden flooring beneath it. If the bathroom is on the second floor, the ceiling of the room beneath the bathroom can be damaged by the water, according to "The First-time Homeowner's Survival Guide."
Repair
Removing water and drying the affected areas as quickly as possible is the first step in repairing damage. Fans can speed the process, according to "A Natural History of Toxic Mold." If vinyl has begun to curl, it will need to be replaced. The drywall of a ceiling can also be replaced, and the ceiling repainted.
Considerations
Repairing water damage is key to avoiding the potential for mold growth. You can wash down damp wooden areas with a mixture of 1/2 cup of bleach in one gallon of water to prevent mold spores from growing, then dry the area thoroughly. Installing a shut-off valve on the toilet's water supply will make it easier for you to prevent a flood if the toilet overflows again in the future.