The incident took place on Monday evening when the girl, after taking permission from her teacher, went to relieve herself in an open area near the government primary school in Gudhora village, about 60 km from the district headquarters, Lavkushnagar police station in-charge ZY Khan said.
When the accused, Pappu Singh, saw her defecating in the open, he got angry and allegedly forced her to pick up her own excreta with her hands, he said.
"The girl later narrated the incident to her parents, following which they, along with other members of the Dalit community, reached the police station to register a complaint against Pappu Singh," the official said.
A case was registered against Mr Singh under sections 374 (unlawful compulsory labour -- unlawfully compelling any person to labour against the will of that person) and 504 (intentional insult with intent to provoke breach of peace) of the Indian Penal Code and relevant section of the Juvenile Justice (Care and Protection of Children) Act, Mr Khan said.
Mr Singh has been missing since the incident and a manhunt has been launched to arrest him, the police official said.