What are the chances of a successful gastric bypass?

Very good. Bariatric surgery has a success rate of about 80-90% for significant weight loss and maintaining that weight loss. Diet and exercise has a success rate of more like 5-10%. Average weight loss with the gastric bypass is about 70-80% of your excess body weight.
70-70% EWL. The average pt loses 70-75% of the weight that they are overweight in 12-18 months. -dr c evanson md fasc fasmbs carmel, in.
100% There is no data to show the success rate of a gastric bypass. However if done by a well trained bariatric surgeon who rule out hiatal hernia and emotional eating this procedure can be 100% successful. Research you surgeon well and good luck.