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.
Mr Singh has been missing since the incident and a manhunt has been launched to arrest him, the police official said.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.