Is Weight Loss Surgery Too Risky?

What are the negative factors involved in gastric bypass operations? Would it be possible to have children if a young woman elected to have the surgery?

– February 10, 2004

Two operations are performed to treat morbid obesity, which is roughly defined as weighing 100 pounds or more above your ideal weight. One is vertical banded gastroplexy, popularly known as “stomach stapling.” The other is gastric bypass (more precisely, the Roux-en-Y procedure). Gastric bypass has become the gold standard of therapy because of the limitations of stomach stapling, which result in less weight loss than the bypass procedure and can fail over time, leading to regained weight or the need for repeat surgery.

Using the bypass procedure, surgeons divide the stomach into unequal parts, with the small part forming a pouch that limits how much one can eat or drink at a given time. This pouch is then connected to the small intestine beyond the area where most food usually is absorbed.

In addition to morbid obesity, the procedure is considered appropriate only for those who are significantly overweight and have a life-threatening condition such as heart disease, diabetes or severe sleep apnea.

The surgery may be lifesaving for those who haven’t been able to lose weight any other way despite repeated attempts. Within the first 18 to 24 months after the operation, most patients lose weight quickly and many maintain a long-term weight loss of as much as 100 pounds. According to the National Institute of Diabetes and Digestive and Kidney Diseases, in one study blood sugar levels in 83 percent of obese patients with diabetes returned to normal after surgery.

Women in their reproductive years who want to have children can do so after the surgery but should wait until their weight stabilizes since rapid weight loss and the nutritional deficiencies that can occur after surgery may harm a developing fetus.

Here are the principal risks of the surgery:


  • Between 10 and 20 percent of patients will require follow-up operations to correct complications, usually an abdominal hernia. Less common complications include breakdown of the staple line and stretched stomach outlets. There are also risks of bowel obstruction and leaking or narrowing of the site where the stomach pouch is reconnected to the small intestine.
  • Some patients develop gallstones, which are always a risk with rapid weight loss. Taking supplemental bile salts for the first six months after surgery can help prevent gallstones.
  • Nearly 30 percent of patients develop such nutritional deficiencies as anemia, osteoporosis and metabolic bone diseases. These problems can usually be avoided by taking the recommended supplements of iron, calcium, vitamin B12 and folic acid, which you will need to continue for the rest of your life.


Andrew Weil, M.D.

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