Gastric bypass (Roux-en-Y)

Gastric bypass, also called Roux-en-Y (roo-en-wy) gastric bypass, involves dividing the stomach to create a small pouch (called the proximal pouch) at the top, and rerouting the small intestine so that it connects to the pouch instead of the larger stomach. This surgery usually takes two to three hours, and most patients stay in the hospital for one to two days.



  • Patients feel less hungry, and they feel full after eating less food.
  • The need for blood pressure or diabetes medications may be reduced.
  • Diabetes remission is higher with gastric bypass than the sleeve.
  • Patients lose 60-80% of their excess weight, on average, in the first 12-18 months.
  • Long-term weight loss is generally greater with gastric bypass than the sleeve.
  • The risk of heartburn is lower with gastric bypass than the sleeve.


  • Bleeding, staple-line leak, infection, blood clots, pneumonia, need for additional surgery, or death.
  • The risk of needing additional surgeries is higher with gastric bypass than sleeve gastrectomy.
  • “Dumping” (food moving too quickly from the stomach to the bowels) may occur, especially after eating foods that are high in sugar or fat.
  • Long-term complications can include strictures, ulcers, hernias, weight regain, vitamin and mineral deficiencies and malnutrition. Most of the long-term problems can be prevented through follow-up with your health care team.