Abdominal surgery, laparoscopic or open, is frequently performed at UPMC Shadyside hospital. One of the most frequent complications following abdominal surgery is a postoperative ileus. Although postoperative ileus may be the result of obstruction or leakage, in most cases postoperative ileus (POI) is the result of local irritation because of fluid overload, exogenous opioids, neurohormonal dysfunction, gastrointestinal stretch, local bleeding and inflammation. POI usually lasts between 2 to 7 days. In most cases, a nasogastric tube (NG tube) is used to relieve that gastric pressure until the resolution of the POI. The placement of a NG tube can lead to a local trauma, bleeding and pain. Pain represents a major complaint among those with POI, often contributing to prolonged hospital stays.

Abdominal surgery, laparoscopic or open, is frequently performed at UPMC Shadyside hospital. One of the most frequent complications following abdominal surgery is a postoperative ileus. Although postoperative ileus may be the result of obstruction or leakage, in most cases postoperative ileus (POI) is the result of local irritation because of fluid overload, exogenous opioids, neurohormonal dysfunction, gastrointestinal stretch, local bleeding and inflammation. POI usually lasts between 2 to 7 days. In most cases, a nasogastric tube (NG tube) is used to relieve that gastric pressure until the resolution of the POI. The placement of a NG tune can lead to a local trauma, bleeding and pain. Pain represents a major complaint among those with POI, often contributing to prolonged hospital stays.

It has been well established that bile function is modulated by the vagal nerve. Therefore, a non-invasive vagal stimulation administered post-operatively may facilitate the resolution of POI, accelerate the return to bile function and shorter the hospital length of stay following major abdominal surgery. Anecdotally, the use of a vagal nerve stimulator has been shown to avoid the placement of a NG tube.

In most cases, postoperative ileus is considered a benign and reversible complication that occurs in 10-30% of patients following abdominal surgery. The use of anesthesia, the use of opioids and anti-inflammatory drugs, hypokalemia, local inflammation, local hematoma, can all contribute to the development of a POI, and its treatment often requires the placement of a NG tube. The placement of a NG tube is not always effective if it is not positioned properly and is associated of a local trauma, misplacement of the NG tube, prolonged pain, and hospital stay. It is always very uncomfortable for the patient. Since the gastro-intestinal motility is regulated by the vagal nerve, the use of non-invasive vagal nerve stimulator may represent an interesting technique to reduce the frequency of this complications associated with the use of a nasogastric tube including local trauma, misplacement and pain on insertion, and constant pain as long as the NG tube remain in place.

Inclusion Criteria:

• Adults (18 and older) undergoing laparoscopic or open colorectal surgery, or any major abdominal surgeries at UPMC Shadyside
• Development of post-operative ileus
• Anticipation of a nasogastric (ng) tube being placed

Exclusion Criteria:

• Pregnant subjects
• Subjects who are unable to read, write, or speak English fluently
• Subjects who have a developmental or neurological disorder and are not cognitively able to provide consent

Subjects will be 2:1 randomized to the Vagal Nerve Stimulator Group or the Placebo Group, respectively.

A blinded study team member will use a standard, active device to establish the threshold of current required to stimulate the vagal nerve via an electrode placed on each side of the neck. The study device will be placed after surgery once an NG tube has been administered. This study device placement and adjustment may happen anywhere from the PACU to the hospital ward level, dependent on the NG tube placement timing, but it will be done in a private setting for confidential safeguards.

According to the standard operative procedure of the vagal stimulator, this current threshold is achieved by (1) increasing the current until the patient feels the sensation, and then (2) reducing the current until the patient no longer feels the current. When this is established, a research-specific device (either active or sham, based on the randomization assignment) will be connected to the elect