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Gastric bypass (Roux-en-Y)

Gastric bypass

What is a gastric bypass?

A gastric bypass, also known as Roux-en-Y gastric bypass (RYGB), is a weight loss surgery that involves creating a small stomach pouch and rerouting the small intestine to this new pouch. This effectively reduces the amount of food the stomach can hold and limits the absorption of calories.

During the surgery, the surgeon divides the stomach into a small upper pouch and a larger lower pouch. The small intestine is then divided and reattached to the small upper pouch, bypassing the larger lower pouch. This means that food consumed will bypass the majority of the stomach and the first section of the small intestine, reducing the amount of calories and nutrients the body absorbs.

This procedure is considered to be more invasive than sleeve gastrectomy, and recovery time is longer. Gastric bypass is a more complex surgery and carries more risks than sleeve gastrectomy, but it also tends to result in more significant weight loss.


Recovery from gastric bypass surgery typically takes several weeks. In the immediate aftermath of the surgery, patients may experience pain and discomfort in the surgical area, as well as nausea and vomiting. Dr Lorenzo will prescribe medication to deal with this. Patients will typically stay in the hospital for several days to be monitored for complications and to begin the process of healing.

After being discharged from the hospital, patients will need to follow a specific diet and exercise plan to ensure proper healing and to help them lose weight. The diet will start with liquids only, then progress to pureed, soft foods and eventually to solid foods. It’s important to note that during the recovery period, patients will have to follow a strict diet plan and eating schedule to avoid complications. Four post-operative dietetics follow-ups are included in our surgery package.

Patients are usually able to return to work and other normal activities within 2-4 weeks after the surgery, but they will need to avoid strenuous activities for several weeks. 

You will also need to attend follow-up appointments with Dr Lorenzo every two weeks until you are on a regular diet so he can monitor your progress and address any complications. You will then see Dr Lorenzo every three months for the first years and every six months in the second year.

Starting six weeks after the operation, you will also see our exercise physiologist for the first of four follow-up consultations.


Obesity surgery, like many other surgeries, is generally safe with minimal complications. However, there are different risks associated with different approaches.

  • Bleeding, infections can occur in any surgery with a risk of <1% for each.
  • Anastomotic leak could happen in 1% of patients undergoing gastric bypass surgery