A gastrojejunostomy (GJ) tube is an enteral feeding device used to provide nutrition, hydration, and medication directly into the small intestine. This device bypasses the stomach, delivering sustenance to the jejunum, the middle section of the small bowel. It is a soft, narrow tube inserted through the skin of the abdomen, designed for long-term nutritional support when oral intake is insufficient or unsafe. The GJ tube’s unique construction allows it to serve two distinct functions simultaneously.
Anatomy and Purpose of the Dual Ports
The physical design of the GJ tube features a dual-lumen structure with two separate channels that exit the body at the same abdominal site. One channel is the gastric port (G-port), which terminates inside the stomach. This port is used primarily to manage the contents of the stomach, rather than for feeding.
The G-port’s main function is gastric decompression, or venting, which removes excess air or fluid from the stomach. This venting action helps relieve symptoms like bloating, nausea, and vomiting caused by poor gastric emptying. Certain medications or fluids tolerated by the stomach may also be administered through this port.
The second channel is the jejunal port (J-port), which extends through the stomach and into the jejunum. This port is used exclusively for delivering liquid nutrition and hydration. Feeding directly into this area ensures nutrient absorption and significantly reduces the risk of reflux and aspiration. The tube is held in place internally by a small, sterile-water-filled balloon and externally by a skin disc or bolster.
Clinical Indications for a GJ Tube
A GJ tube is selected when a standard gastrostomy tube (G-tube), which feeds directly into the stomach, is unsuitable. Bypassing the stomach is the primary reason for choosing this device. One common indication is severe gastric dysmotility, such as gastroparesis, where the stomach muscles cannot empty contents normally.
Chronic, severe vomiting or persistent gastroesophageal reflux disease (GERD) also indicates the need for a GJ tube to mitigate the risk of pulmonary aspiration. Aspiration occurs when stomach contents back up into the esophagus and are inhaled into the lungs, potentially causing pneumonia. Delivering formula directly into the small intestine prevents the reflux of feed into the upper digestive tract.
The tube is also used for patients requiring simultaneous feeding and gastric decompression. The stomach may need continuous draining to manage pressure or fluid buildup, but the patient still requires nutritional support. The dual-port GJ tube makes it possible to address both needs through a single abdominal stoma site, avoiding the need for two separate access tubes.
The Insertion Process
The placement of a GJ tube is performed by an interventional radiologist or gastroenterologist using imaging guidance. The procedure is typically done under conscious sedation, meaning the patient remains responsive. The initial step involves creating a stoma, a small opening through the abdominal wall into the stomach, if one does not already exist.
Using X-ray guidance (fluoroscopy), the physician carefully threads the long, thin jejunal portion of the tube through the stomach and past the pylorus. The pylorus is the valve connecting the stomach to the small intestine. The tip of the J-port is then positioned precisely within the jejunum.
Once the tube is correctly located, the internal retention balloon is inflated with sterile water to secure the tube against the stomach wall. Placement of both the G-port in the stomach and the J-port in the jejunum is confirmed with a final injection of contrast dye and additional imaging. The procedure generally takes about one hour, and the patient must be monitored closely afterward before feedings can begin.
Routine Care and Maintenance
Day-to-day care of a GJ tube is essential for preventing complications, focusing primarily on maintaining the health of the stoma site. The skin around the tube requires daily cleaning with warm water and a mild, non-irritating soap. It is important to gently clean under the external bolster or disc, ensuring the area is completely rinsed and patted dry to prevent skin irritation and infection.
Proper flushing is the most important action for preventing tube blockage, especially for the J-port. Both the G-port and J-port must be flushed with a specific amount of water before and after every administration of feed or medication. Since the jejunal lumen is narrower, meticulous flushing is necessary to maintain its patency.
The tube must be secured to the body with an external device or tape to prevent accidental tugging or dislodgement, which is a serious complication requiring immediate medical attention. Caregivers should routinely inspect the skin for signs of infection, such as increasing redness, warmth, or thick discharge. GJ tubes typically require scheduled replacement every three to six months to prevent material degradation and failure of the retention balloon.