What happened to Abbott when he tried to run away from the juvenile center in the book, In the Belly of the Beast: Letters from Prison?

Abbott notes that when he was first brought to the center, he attempted to flee and was knocked on the head and dragged back. He was then brought to the basement, flung down the stairs, and ordered to strip, after which, the guard inspect Abbott's anus and privates for contraband. Finally, they take to his basement cell for solitary confinement.