A young girl sits in my office, describing the "swishy" feeling that she gets in her stomach when she's at school. It tends to happen at drop-off, just after lunch and as she watches the clock tick toward the end of the day. It happens so often that she knows she's not actually sick, but it bothers her just the same. She can't find a way to make it go away, and that makes it hard to concentrate. The thing is, she actually is sick to her stomach. This 7-year-old is, quite literally, worried sick.