This study will determine the ability of the device to draw a small amount of gas from an insufflated abdomen during laparoscopic surgery and accurately detect if gaseous content from the bowel is present.

Undetected bowel perforation is a rare but dangerous complication of laparoscopic surgery. If the injury is not detected and treated at the time of the surgical procedure, the patient can suffer sever complications including septic shock and eventually death. Our goal is to test a novel device that can detect bowel gas leakage from a perforation and alert the surgeon during the operation by evaluating the gases present in the insufflated abdomen during surgery. During laparoscopic surgery, carbon dioxide in inserted in the abdominal cavity in order to perform the operation. This is dynamic process as insufflation is a constant during the entire procedure to maintain a constant pressure and compensate small leaks due to the insertion and retrieval of instruments.

This study will determine the ability of device to be attached to a standard Veress needle or trocar during the operation and periodically draw a small amount of gas from the abdomen to evaluate the gas and accurately detect gaseous content from the bowel. Before the device can be used to detect bowel perforations, first we must ensure that it can accurately detect bowel gas in an insufflated abdomen.

Inclusion Criteria:

1. Age 18 - 60 years old with the diagnosis of morbid obesity, who qualifies for laparoscopic gastric bypass surgical therapy, and has elected to undergo laparoscopic gastric bypass surgery.
2. Receiving care in the Stanford Hospital General Surgery Bariatric Surgery Clinic under the care of Dr. Dan Azagury
3. The patient is scheduled for laparoscopic roux en y gastric bypass surgery, with Dr. Azagury.
4. Willing and cognitively able to sign informed consent.

Exclusion Criteria:

1. Lack of or inability to provide informed consent.
2. Less than 18 years of age or greater than 60 years of age
3. Planned deviation from the standard laparoscopic gastric bypass operation
4. Conversion intra-operatively from a laparoscopic gastric bypass to an alternative laparoscopic surgical operation or to an open gastric bypass operation.
5. Enrollment in another device or drug study that may confound results.