"He went to another teacher to try to receive help and she proceeded to place a garbage bag on him to make an example out of him of what you should not do at school, instead of calling us and saying 'can you please bring him a change of clothes'," his mum told reporters.
According to the family's lawsuit, the boy was humiliated again in March this year when he was allowed out of the classroom for a bathroom break, but locked out when he tried to get back in.
Mongol said her son has since transferred to a different school, but the mental wounds have yet to fade.
"He doesn't understand why when he went to adults for help they would do this to him, so it's had a lasting effect on him," she said.
Mongol claimed she was never notified by the school about the incident, the school district said it reported the matter to law enforcement when it was first notified, and the incident is now the subject of an administrative investigation.
The mother is reportedly seeking damages for extreme negligence and creating a hostile environment.