Why can i slosh my stomach? Can other people do this?

When i lay down i can wiggle my stomach inside of me and you can hear a noise like splashing water. People can hear it from all the way across the room. I dont even have to drink a gl of water before or had a lot of water today, i can do it nearly all the time. Can anyone else out there do this? no one i know can do this. Do you know why it does this, or am i just some kind of mutant?