bottom surgery
n.— «Rey always expected to go off-campus for his transition. He wound up being operated on by a private surgeon in New York City. (He received no “bottom surgery,” as it is known—few transmen do, in part because the operation is thought to be too rudimentary and in part because many transmen view it as unnecessary.)» —“When Girls Will Be Boys” by Alissa Quart New York Times Magazine Mar. 16, 2008. (source: Double-Tongued Dictionary)