A gastrojejunostomy tube is used when a patient's stomach must be bypassed, with nutrients and/or medication being delivered directly to the jejunum. In this situation, the stomach commonly fills with stomach acid and digestive enzymes, which may cause vomiting, acid reflux or other esophageal problems. The gastrojejunostomy drainage bag is provided to allow the contents of the stomach to be drained through the gastrojejunostomy tube, rather than building up within the patient's stomach. The gastrojejunostomy drainage bag includes a receptacle having a lower portion and an upper stem portion, the upper stem portion terminating in a port adapted for connection to the gastrojejunostomy tube. Preferably, a lower port is formed through the lower portion, allowing the contents of the gastrojejunostomy drainage bag to be selectively emptied. A method of releasing gas or trapped air from the stomach is also disclosed.