What Happens During Laparoscopic Gastric Bypass?

Laparoscopic gastric bypass is one of the most popular weight-loss surgeries in the world. It is sometimes called the Roux-en-Y gastric bypass (RYGB), and it is performed on thousands of patients each year to help them reach their health goals. In addition to weight loss, laparoscopic gastric bypass often helps patients resolve their diabetes, lower their blood pressure and cholesterol, and feel more energetic. This blog describes what happens during the RYGB procedure.

The Laparoscopic Approach: Minimally-Invasive for Easier Healing

The laparoscopic approach allows your surgeon to alter your digestive system using only a few (4-5) small incisions. Once the incisions are made, small cameras are inserted using thin tubes, and air is added to the abdominal cavity to create room to work and greater visibility. Your surgeon will be able to perform the surgery by looking at the monitors connected to the cameras.

Altering the Digestive Tract: The Restrictive and Malabsorptive Elements of the Surgery

After your surgeon can clearly visualize your stomach and small intestine from multiple angles using the laparoscopically-placed cameras, it is time to begin altering your digestive tract. During the “restrictive” element of the surgery, your surgeon will divide your stomach into two parts using staples – a smaller upper pouch that becomes the new stomach and the larger lower portion that will be “bypassed.”

Creating this division in your stomach has multiple effects.  The upper pouch fills quickly, allowing only a small amount of food to be consumed at a time. The stomach stretches as it fills, giving you a feeling of satiety with much less food intake. While the lower portion of the stomach will no longer receive food, it is still able to secrete digestive enzymes that will help to break down your food.

Once the stomach is partitioned, and the new smaller stomach is created, the lower portion of the small intestine is detached and pulled up to connect with the upper stomach portion. This creates a bypass not only of the lower stomach pouch but also of the upper intestine, which is reconnected further down the small intestine (creating the Y-shape).  Bypassing the upper intestine reduces the amount of calories absorbed, contributing to overall post-surgical weight-loss. This part of the procedure is known as the “malabsorptive” element. Since you will not be absorbing 100% of the vitamins, minerals, proteins, fats, and carbohydrates you consume through food, you will work closely with our dietitian to make sure you are taking in adequate protein supplements, vitamins, and minerals to keep you healthy.

The restrictive and malabsorptive elements of the Roux-en-Y gastric bypass make the procedure one of the most effective solutions for long-term weight loss. It has been proven to be as safe as gastric banding or sleeve gastrectomy (Lynn et al 2018) while providing patients with more weight loss over the long-term following surgery (Golzarand et al 2017).

If you would like to  find out more about procedures that could help you in your weight-loss journey, contact the Chicago Institute for Advanced Bariatrics at 773.327.6800 to discover whether laparoscopic gastric bypass is a good option for you!


Golzarand, M., Toolabi, K., and Farid, R. (2017). The bariatric surgery and weight losing: a meta-analysis in the long- and very long-term effects of laparoscopic adjustable gastric banding, laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy on weight loss in adults. Surgical Endoscopy. 31(11): 4331-4345.

Lynn, W., Ilczyszyn, A., Rasheed, S., Davids, J., Aguilo, R., and Agrawal, S. (2108). Laparoscopic Roux-en-Y gastric bypass is as safe as laparoscopic sleeve gastrectomy. Results of a comparative cohort study. Annals of Medicine and Surgery. 35:38-43.