IN THE NUBA MOUNTAINS, Sudan — IF you subscribe to the caricature of devout religious believers as mostly sanctimonious hypocrites, the kind who rake in cash and care about human life only when it is unborn, come visit the doctor here.

Dr. Tom Catena, 51, a Catholic missionary from Amsterdam, N.Y., is the only doctor at the 435-bed Mother of Mercy Hospital nestled in the Nuba Mountains in the far south of Sudan. For that matter, he’s the only doctor permanently based in the Nuba Mountains for a population of more than half a million people.

Just about every day, the Sudanese government drops bombs or shells on civilians in the Nuba Mountains, part of a scorched-earth strategy to defeat an armed rebellion here. The United States and other major powers have averted their eyes, so it is left to “Dr. Tom,” as he is universally known here, to pry out shrapnel from women’s flesh and amputate limbs of children, even as he also delivers babies and removes appendixes.