Bariatric surgery is booming in the United States, but experts say that more patients should be told about the potentially serious side effects of the surgery. Between 30 percent and 40 percent of the 200,000 surgeries performed every year in the country include complications such as hernias, infections, pneumonia, and bariatric connection problems. More problematic, experts say, is that no one knows why some patients react badly to the surgery and others do not. But they stress that patients...