Every year, more than 25,000 Americans undergo surgery to correct a hiatal hernia, a condition in which tissue from the stomach bulges into the chest cavity through a hole in the diaphragm. The hernias often return, but major complications are rare. Hospital stays are usually short. Irene Smith, a 42-year-old cafeteria worker, wife of an Army sergeant and mother of three, was considered a good candidate for the procedure when she was evaluated in late 2007. A cardiologist's report was especially positive. "Lost about 25 pounds, exercising daily, looks fantastic," he wrote.