When I go to someone house to sleepover, wherever I'm sleeping, for some reason I'm not able to sleep and as the night goes on my stomache starts to ache and it feels like it's being sucked in really hard though I'm breathing properly. This usually happens when I breathe out. Happens in every position I lay in.
For example, if you lie down on your stomach and suck in as far as you can and add pain, that is what it feels like.