Intensive care patients usually suffer from intra-abdominal hypertension that can lead to abdominal compartment syndrome (ACS). ACS affects the normal functioning of several organs and systems (including brain perfusion). Among its effects, we find the formation of bacterial-caused gases in the intestine. It has been suggested that monitoring the volume of intraintestinal gas may contribute to understanding and treating the evolution of ACS. To date, intestine gas can be estimated using Computerized Tomography. In this work, we propose to harness the versatility of microwave reflectometry as a novel method for quantifying intraintestinal gas in critical care patients. The abdominal wall and intestine can be modeled as a compound of parallel dielectric slabs. The appearance of gas instead of other fluids has a direct effect on the overall scattering parameters. A numerical analysis based on finite-elements methods of simulation is presented as a proof-of-concept of the monitoring.