hiatal hernia

Is there any way a home to figure out if my son has a hiatal hernia?

A chiropractor said she felt one a year ago, but we didn't go back to her for other reasons. He had an endoscopy that showed nothing, but the gastro doc said with an empty stomach and the fact that, if it does exist, it goes in and out, that this may not mean anything. So, not seeing one doesn't mean it doesn't exist.

Any ideas you have would be helpful.

Thank you.