The Mini Gastric Bypass (MGB) is a short, simple, successful and inexpensive laparoscopic gastric bypass weight loss surgery. The operation usually takes only 30 min., hospitalization less than 24 hours. More Effective than the LapBand / Safer than the RNY Gastric Bypass... The Mini Gastric Bypass is low risk, has excellent long term weight loss, minimal pain and can be easily reversed or revised. 3,255 people from all across America and around the world are choosing the MGB as the Best in Bariatric Surgery.