Abdominal pain associated with gastroenteritis... why does it come in fresh waves whenever I change my position/roll over in bed?

Been sick since Tuesday… Horrible stomach flu. I noticed that the abdominal pain would settle until I rolled over or even slightly changed the position of my stomach area and then it’s like pop rocks and soda… Violent pain. At that point I head to the bathroom, it settles down… But if I don’t get back in bed in precisely the position I want I’m screwed because as soon as I move, it starts again. And let’s not even discuss trying to stretch out and lie flat on my back.

What causes this? What about just moving makes the pain return?