A method for evaluating a gastrointestinal tract of a subject may comprise using a sensor located in the subject to obtain data regarding qualities of a tissue of the gastrointestinal tract； using the obtained data, determining a measure of perfusion of blood in the tissue； using the obtained data, determining a measure of thickness of the tissue； using the measure of perfusion and the measure of thickness, determining a measure of inflammation of the tissue； and using one or more of the measure of perfusion, the measure of thickness, and the measure of inflammation, classifying a state of the tissue.
