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

The first step is sleeve gastrectomy in which about 80 percent of the stomach is removed, leaving a smaller tube-shaped stomach, similar to a banana. However, the valve that releases food to the small intestine (the pyloric valve) remains, along with a limited portion of the small intestine that normally connects to the stomach (duodenum).

The second step bypasses the majority of the intestine by connecting the end portion 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 performed as a single procedure; however, in select 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 more 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 potentially life-threatening weight-related health problems, including:

• Heart disease
• High blood pressure
• High cholesterol
• Severe sleep apnea
• Type 2 diabetes
• Stroke
• 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 must also 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 potential health risks, both in the short term and long term.

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

• Excessive bleeding
• Infection
• Adverse reactions to anesthesia
• Blood clots
• Lung or breathing problems
• Leaks in your gastrointestinal system

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

• Bowel obstruction
• Dumping syndrome, causing diarrhea, nausea or vomiting
• Gallstones
• Hernias
• Low blood sugar (hypoglycemia)
• Malnutrition
• Stomach perforation
• Ulcers
• Vomiting

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

If you qualify for a BPD/DS, your health care team gives you instructions on how to prepare for surgery. You may need to have various lab tests and exams before surgery.

Food and medications

Before your surgery, give your surgeon and any other health care providers a list of all medicines, vitamins, minerals, and herbal or dietary supplements you take. You may have restrictions on eating and drinking and which medications you can take.

If you take blood-thinning medications, talk with your doctor before your surgery. Because these medications affect clotting and bleeding, your blood-thinning medication routine may need to be changed.

If you have diabetes, talk with the doctor who manages your insulin or other diabetes medications for specific instructions on taking or adjusting them after surgery.

Other precautions

You may be required to start a physical activity program and to stop any tobacco use.

You may also need to prepare by planning ahead 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 performed laparoscopically, your hospital stay may last around two days.

Before the procedure

Before you go to the operating room, you will change into a gown and will be asked several questions by both doctors and nurses. In the operating room, you are given general anesthesia before your surgery begins. Anesthesia is medicine that keeps you asleep and comfortable during surgery.

During the procedure

The specifics of your surgery depend on your individual situation and your doctor's practices. Some surgeries are done with traditional large, or open, incisions in your abdomen, while some may be performed laparoscopically, which involves inserting instruments through multiple small incisions in your abdomen.

• The first step of a BPD/DS. The first step in a BPD/DS involves removing a portion of the stomach. After making the incisions with the open or laparoscopic technique, your surgeon removes a large portion of the stomach and forms the remaining portion into a narrow sleeve. Your surgeon leaves intact the valve that releases food to the small intestine (the pyloric valve), along with a limited portion of the small intestine that normally connects to the stomach (duodenum).
• The second step of a BPD/DS. During the second step, your surgeon makes one cut through the part of the small intestine just below the duodenum, and a second cut farther down, near the lower end of the small intestine. Then your 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 part 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 B12. 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 three to six 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 percent 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 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 can also 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, you may have inadequate weight loss. 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 you develop complications after your surgery, see your doctor immediately.