WEDNESDAY, June 15 (HealthDay News) -- Weight loss surgery patients who are discharged from the hospital too soon after undergoing gastric bypass have an increased risk of complications and death, a new study has found.

After analyzing data from nearly 52,000 gastric bypass patients, researchers found that those released from the hospital the day of surgery were 12 times more likely to have serious complications (1.9 percent versus 0.16 percent) and 13 times more likely to die than patients who left the hospital after the U.S. average of a two-day stay.

The death rate within 30 days of discharge was 0.1 percent for those who stayed in the hospital for two or more days, versus 0.8 percent for those who left the day of surgery.

Patients who were discharged from the hospital less than 24 hours after an overnight stay were two times more likely to die within 30 days than those who remained in hospital for two days after their surgery, the investigators found.

Like all surgeries, bariatric surgery carries surgical risks, including serious infections, internal bleeding, blood clots, and death, according to the American Society for Metabolic & Bariatric Surgery (ASMBA).

Length of stay appeared to be a greater risk factor than age, gender, race, body mass index and obesity-related conditions, the researchers noted.

The study was scheduled for presentation Wednesday at the annual meeting of the American Society for Metabolic & Bariatric Surgery, in Orlando, Fla. Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

"This study shows what a difference a day makes," co-author Dr. John Morton, an associate professor of surgery and director of bariatric surgery at Stanford Hospital & Clinics at Stanford University, said in an ASMBS news release.

"A two-day length of stay appears reasonable for most people and results in a safety profile that rivals gallbladder or hip replacement surgery. To reduce it further may put patients at an increased chance of unnecessary risk," said Morton, who is chair of the ASMBS Access to Care Committee. "A patient should be discharged based on his or her individual risk profile. We counsel our patients to avoid drive-thru fast food, and also advise against drive-thru gastric bypass."

"Bariatric surgery is safer than ever, but discharging patients too soon after surgery may be pushing the envelope too far and may have serious consequences," he added.

More information

The U.S. National Library of Medicine has more about gastric bypass surgery.