An enteral tube includes a built-in Gastric Residual Volume (GRV) detection sensor at the distal end and a GRV indicating device at the proximal end for indicating the current GRV without requiring the aspiration of any stomach contents. The enteral tube with integrated GRV detection sensor is flexible and long enough to be looped around within the stomach. Weights may be employed to keep the sensor located generally at the lowest portion of the gastric cavity. The GRV detection sensor may include a sealed air column terminating with a flexible membrane. When the enteral tube and sealed air column are inserted into the stomach and submerged in gastric contents, pressure is exerted against the flexible membrane, and therefore against the sealed air column. A pressure sensor detects the pressure within the sealed air column and provides a signal or level representative of the amount of gastric contents in the stomach.