Atmospheric pressure is applied to the entire body as so does not favor the flow of fluid from one part to another. There is no alteration of the pressure gradients involving the flow of blood either arteries or veins.
Fluids including edema fluid is not compressible. Gases are compressible so gas in a confined space with expand with negative pressure and contract with positive pressure. The middle ear contains air under normal circumstances but contains fluid when diseased.
The bowels often contain air. Generally the gas can be relieved with any expansion without causing injury. A possible closed loop bowel obstruction could theoretically expand to the extent that gas is withing the closed loop.