Risks of Weight Loss Surgery

What have YOU got to lose?

Statistics once showed  that 1 in 300 died from gastric bypass surgery, but recent statistics indicate the procedure has become much safer due to better methods of performing both roux-en-y and laparoscopic gastric bypass.  People who suffer from morbid obesity can have other serious medical conditions which are related to or caused by being overweight.

The higher your BMI is, the more likely it is that other medical problems will exist. Other medical problems can increase the risk of complications from gastric bypass surgery and the recovery period after gastric bypass surgery. Another risk factor is age, although this increases the need for surgery there is generally a higher risk. Any medical procedure that involves humans and reactions to stress, trauma, drugs, and other causes, unpredictable negative results can and will occur. This surgery should be considered only after many attempts with other diet control and exercise have failed. Diet and exercise will be required before and after this surgery.

Statistical data associated with this gastric bypass surgical procedure include:  failure to lose weight (about 10%), some complication of surgery (10% - 15%), serious, life-threatening complication (about 2% - 3%), and even death (less than 1%).  On the other hand, the risks associated with morbid obesity far outweigh the risks associated with surgery.  

For example, studies prove that the individual who is 100% over ideal weight has a risk of mortality that is ten times that of a slender counterpart (meaning that an obese individual's chance of dying is ten times as great in any given year). There is no question that the potential benefits of surgery outweigh the risks.

Since gastric bypass surgical procedures result in some loss of absorptive function, the long-term consequences of potential nutrient deficiencies must be recognized and adequate monitoring must be performed, particularly with regard to vitamin B12, folate, and iron. Some patients may develop other gastrointestinal symptoms such as "dumping syndrome" or gallstones.

Occasionally, patients may have postoperative mood changes or their pre-surgical depression symptoms may not be improved by the achieved weight loss. Thus, surveillance should include monitoring of indices of inadequate nutrition and modification of any preoperative disorders. The table below illustrates some of the complications that can occur following gastric bypass surgery.

Recommendation: Gastric bypass surgery is an option for carefully selected patients with clinically severe obesity (BMI 40 or 35 with comorbid conditions) when less invasive methods of weight loss have failed and the patient is at high risk for obesity-associated morbidity or mortality. Evidence Category B.

After gastric bypass surgery, an occasional patient may have a complication relating to the staple line or the outlet of the pouch. For example, there might be leakage, perforation, or bleeding where some staples are dislodged by overstretching of the pouch. Other possible complications are formation of an ulcer or stricture or failure of the staple line to heal properly. These kinds of problems might make additional surgery necessary. Though all precautions are taken to prevent them, complications occasionally occur.

For the first month or so, the patient may experience nausea and vomiting until he or she becomes accustomed to the new small stomach. Afterwards, patients enjoy a feeling of satisfaction with small amounts of food.

About one out of twenty-five patients may need to be readmitted to the hospital because of vomiting. In the first few weeks after surgery, vomiting may be caused by swelling at the operative site. Later, there is a possibility that vomiting might be caused by formation of a stricture, by scarring of the outlet of the stomach pouch, or by obstruction of the pouch outlet by a lump of poorly chewed food, tablet, or other foreign body. In most cases these complications can easily be corrected, without additional formal surgery.

Because of the limitation of food intake, supplemental vitamins must be taken. Vitamin supplementation will always be necessary to minimize the risk of anemia, weakness, muscular un-coordination, and clinical depression. During the first few weeks following surgery, a liquid or chewable vitamin is advised. Afterwards, any good multivitamin preparation containing adequate amounts of the B-complex vitamins and minerals is sufficient.


There is some evidence that babies may be born with congenital abnormalities when there is rapid weight loss during pregnancy. Therefore, pregnancy should be avoided until weight has stabilized. Once weight has stabilized, there are no contraindications to pregnancy.