There are multiple types of bariatric surgery, each with its own set of advantages and disadvantages. It's important to have a discussion with your doctor about which procedure would be best for you. Here is an overview of some common surgeries:  

• Roux-en-Y (roo-en-wy) gastric bypass. Roux-en-Y (roo-en-wy) gastric bypass surgery is the most common type of bypass surgery. This procedure is typically not reversible and works by decreasing the amount of food you can eat in one sitting, as well as reducing the absorption of nutrients. The surgeon will make a cut across the top of the stomach, sealing it off from the rest of the stomach. The resulting pouch will be about the size of a walnut and can only hold around an ounce's worth of food. Normally, a person's stomach can hold up to 3 pints worth of food. Then, the surgeon cuts a section of the small intestine and sews it directly onto the stomach pouch. This allows food to bypass most of the stomach and enter directly into the middle part of the small intestine.
• Sleeve gastrectomy. Sleeve gastrectomy is a weight-loss surgery that removes about 80% of the stomach, leaving behind a long, tube-like pouch. This smaller stomach can't hold as much food and produces less of the hormone ghrelin, which regulates appetite. The advantages of this procedure include no rerouting of the intestines and significantly reduced hunger cravings. Sleeve gastrectomy also requires a shorter hospital stay than most other procedures.
• Biliopancreatic diversion with duodenal switch. This surgery is split into two sections. The first being comparable to a sleeve gastrectomy then connecting the end of the intestine near the stomach in order to bypass most of it (duodenal switch and biliopancreatic diversion). This surgery both restricts how much you can eat and reduces the absorption of nutrients. While it is extremely effective, it has greater risks, including malnutrition and vitamin deficiencies.

 

After bariatric surgery

After weight-loss surgery, you generally won't be allowed to eat for 1 to 2 days so that your stomach and digestive system can heal. Then, you'll follow a specific diet for a few weeks. The diet begins with liquids only, then progresses to pureed and very soft foods and eventually to regular foods. You may have many restrictions or limits on how much and what you can eat and drink. You'll also have frequent medical checkups to monitor your health in the first several months after weight-loss surgery. You may need laboratory testing, blood work and various exams.

Results

Gastric bypass and other bariatric surgeries can provide long-term weight loss. The amount of weight you lose depends on your type of surgery and your change in lifestyle habits. It may be possible to lose half, or even more, of your excess weight within two years. In addition to weight loss, gastric bypass surgery may improve or resolve conditions often related to being overweight, including:

• Heart disease
• High blood pressure
• Obstructive sleep apnea
• Type 2 diabetes
• Nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH)
• Gastroesophageal reflux disease (GERD)
• Joint pain, also called osteoarthritis

Gastric bypass surgery can also improve your ability to perform routine daily activities, which could help improve your quality of life.