Supreme Court Justice Ruth Bader Ginsburg returned to work Monday after missing a day of courtroom arguments last week. Chief Justice John Roberts said last week that the 86-year-old was “indisposed due to illness.” A court official later specified that Ginsburg was “home with a stomach bug.” She has in recent years had surgeries for lung cancer and treatment for a cancerous tumor on her pancreas. The justice has said she plans to stay on the high court as long as her health allows.