A biliopancreatic diversion with duodenal switch (BPD/DS) is a less common weight-loss procedure that is done in two major steps.

The first step is sleeve gastrectomy in which about 80% of the stomach is removed. This leaves a smaller tube-shaped stomach the size of a banana. The valve that releases food to the small intestine, called the pyloric valve, remains. A limited part of the small intestine that connects to the stomach, called the duodenum, also remains.

The second step changes the digestive tract to bypass most of the intestine by connecting the end part of the intestine to the duodenum near the stomach. A BPD/DS both limits how much you can eat and reduces the absorption of nutrients, including proteins and fats.

BPD/DS is generally done as a single procedure; however, in some circumstances, the procedure may be performed as two separate operations — sleeve gastrectomy followed by intestinal bypass once weight loss has begun.

While a BPD/DS is very effective, it has risks, including malnutrition and vitamin deficiencies. This procedure is generally recommended for people with a body mass index (BMI) greater than 50.

A BPD/DS is done to help you lose excess weight and reduce your risk of possibly life-threatening weight-related health problems, including:

• Heart disease.
• High blood pressure.
• High cholesterol.
• Severe sleep apnea.
• Type 2 diabetes.
• Stroke.
• Cancer.
• Infertility.

A BPD/DS is typically done only after you've tried to lose weight by improving your diet and exercise habits.

But a BPD/DS isn't for everyone who is severely overweight. You likely will have an extensive screening process to see if you qualify.

You also must be willing to make permanent changes to lead a healthier lifestyle both before and after surgery. This may include long-term follow-up plans that involve monitoring your nutrition, your lifestyle and behavior, and your medical conditions.

Check with your health insurance plan or your regional Medicare or Medicaid office to find out if your policy covers weight-loss surgery.

As with any major surgery, a BPD/DS poses possible health risks, both in the short term and the long term.

Risks associated with BPD/DS are similar to those of any abdominal surgery and can include:

• Excessive bleeding.
• Infection.
• Reactions to anesthesia.
• Blood clots.
• Lung or breathing problems.
• Leaks in the gastrointestinal system.

Longer term risks and complications of a BPD/DS may include:

• Blockage of the bowel, called an obstruction.
• Dumping syndrome, which can cause diarrhea, nausea or vomiting.
• Gallstones.
• Hernias.
• Low blood sugar, known as hypoglycemia.
• Malnutrition.
• Stomach perforation.
• Ulcers.
• Vomiting.
• Ongoing diarrhea.

Rarely, complications of a BPD/DS can be fatal.

In the weeks leading up to your surgery, you may be required to start a physical activity program and to stop any tobacco use.

Right before your procedure, you may have restrictions on eating and drinking and which medicines you can take.

Now is a good time to plan for your recovery after surgery. For instance, arrange for help at home if you think you'll need it.

BPD/DS is done in the hospital. The length of your hospital stay will depend on your recovery and which procedure you're having done. When the surgery is performed laparoscopically, your hospital stay may last around 1 to 2 days.

During the procedure

The specifics of your surgery depend on your individual situation and your surgeon's practices. Some surgeries are done with traditional large cuts in your belly. This is called open surgery. Some surgeries may be performed laparoscopically. This involves placing instruments through multiple small cuts in the belly.

You are given general anesthesia before your surgery begins. Anesthesia is medicine that keeps you asleep and comfortable during surgery.

• The first step of a BPD/DS. The first step in a BPD/DS involves removing part of the stomach. After making the cuts with the open or laparoscopic technique, the surgeon removes a large portion of the stomach and forms the remaining portion into a narrow sleeve. The surgeon leaves intact the valve that releases food to the small intestine, known as the pyloric valve. A limited part of the small intestine that connects to the stomach, called the duodenum, also is left intact.
• The second step of a BPD/DS. During the second step, the surgeon makes one cut through the part of the small intestine just below the duodenum. A second cut is then made farther down, near the lower end of the small intestine. Then the surgeon brings the cut end near the bottom of the small intestine up to the other cut end, just below the duodenum. The effect is to bypass a large segment of the small intestine.

Each step of the surgery usually takes a few hours. After surgery, you awaken in a recovery room, where medical staff monitors you for any complications.

After the procedure

Immediately after a BPD/DS procedure, you may have liquids but no solid food as your stomach and intestines begin to heal. You'll then follow a special diet plan that changes slowly from liquids to pureed foods. After that, you can eat soft foods, then move on to firmer foods as your body is able to tolerate them.

Your diet after surgery may continue to be quite restricted, with specified limits on how much and what you can eat and drink. Your doctor will recommend that you take vitamin and mineral supplements after surgery, including a multivitamin, calcium and vitamin B-12. These are vital to prevent micronutrient deficiency.

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, bloodwork and various exams.

You may experience changes as your body reacts to the rapid weight loss in the first 3 to 6 months after a BPD/DS, including:

• Body aches.
• Feeling tired, as if you have the flu.
• Feeling cold.
• Dry skin.
• Hair thinning and hair loss.
• Mood changes.

After a BPD/DS, it may be possible to lose 70% to 80% of your excess weight within two years. However, the amount of weight you lose also depends on your change in lifestyle habits.

In addition to helping with weight loss, a BPD/DS may improve or resolve conditions often related to being overweight, including:

• Gastroesophageal reflux disease.
• Heart disease.
• High blood pressure.
• High cholesterol.
• Obstructive sleep apnea.
• Type 2 diabetes.
• Stroke.
• Infertility.

A BPD/DS also can improve your ability to perform routine daily activities, which could help improve your quality of life.

When weight-loss surgery doesn't work

It's possible to not lose enough weight or to regain weight after weight-loss surgery. This weight gain can happen if you don't follow the recommended lifestyle changes. If you frequently snack on high-calorie foods, for instance, weight loss can stall. To help avoid regaining weight, you must make permanent healthy changes in your diet and get regular physical activity and exercise.

It's important to keep all of your scheduled follow-up appointments after weight-loss surgery so your doctor can monitor your progress. If you notice that you aren't losing weight or if you develop complications after your surgery, see your doctor immediately.