What is the difference between gastric sleeve and gastric bypass and which surgery is better for weight loss?

Fundamental: Sleeve is a purely restrictive where bypass is a combination of restrictive and malabsorption procedure. Bypass has a longer history and is considered a durable procedure for long term management of morbid obesity.

Both are great, but: Both take about one hour, laparoscopic. Usually home the next day. As safe as appendectomy (with experienced surgeon). Weight loss at one year is 80% for bypass and 70% for sleeve. Bypass ideal for bad reflux or bad diabetes. Sleeve has fewer problems with sugar, but mild risk reflux. Talk to your surgeon for more details.