This operation is the most common gastric bypass procedure. It was first performed for weight loss 30 years ago. First, a small stomach pouch is created by stapling or by vertical banding. This causes restriction of food intake. Next, a section of the small intestine is attached to the pouch, to allow food to pass to the intestines. However, the initial portion of the intestines is “bypassed” and the stomach pouch is attached to the lower portion of the intestines. This causes mildly reduced calorie and nutrient absorption.
You will certainly eat differently. Patients experience significant lack of hunger after the gastric bypass. This is most significant immediately after the operation, but improves some with time. Patients also become very full (satiated) after eating small amounts of food. After a gastric bypass people generally are satisfied with the foods that they eat, they generally can eat regular food (with the exception of sweets) and many of their previous cravings are gone. In the first several months of the operation, patients have to adapt suddenly to their new eating style. There is a lot of trial and error in food selection. Within a few months, eating is much easier.
Dumping usually occurs when concentrated sugar, or highly concentrated carbohydrates enter the upper intestine without being broken down by pancreatic juice and bile. Since these fluids mix with ingested food further downstream than usual after the gastric bypass, dumping generally occurs if a patient eats concentrated sweets. The syndrome typically involves 15 minutes to one hour of intestinal cramping, diarrhea, sweating, a fast heart rate and other side effects. Dumping can sometimes happen with other foods as well. Dumping does not occur after gastric band placement or the BPD-DS. We view dumping a good side effect that improves patient’s weight loss.
On average, after a gastric bypass, patients will loss about 70-80 percent of their excess weight during a 2-year period. Weight loss is extremely rapid after the first 6 months and then tapers down. Some patients will regain 5-10 percent of their excess weight during the two to five year marks. The reason for this weight regain in some patients is complex and poorly understood. Long-term studies have consistently documented the persistent of weight loss over a ten- to twenty-year follow-up. This is one of the best-studied operations for weight loss.
The most common late complications after a gastric bypass is iron deficiency anemia. Menstruating women will need to take an iron supplement. All other patients can have a multivitamin with iron. Osteoporosis may occur at a higher frequency in gastric bypass patients, calcium supplements are recommended in some patients. Rarely, hernias can occur long after a gastric bypass. These may require operative interventions.
In the first several months after a gastric bypass, two percent of patients develop strictures. This is scarring between the stomach and the intestine. People notice that liquids “go down” easily, but solids tend to stick. This complication can be easily remedied by an endoscopy performed by the gastroenterologist in the office. Ulcers occur in some patients – especially smokers and patients that take NSAIDS (Motrin, Aleve, Advil, Naproxen, etc…) Ulcers can cause bleeding or pain. Medications often help ulcers heal.
In the first week of a gastric bypass several potential complications are possible. Death is a very rare event in experienced centers. We have never had a death. The death rate is about 1/500 – 1/1000. The most common cause of death is a pulmonary embolism (PE). PE’s can occur after any general anesthesia and major operation. Early mobilization and the use of blood thinners can decrease the likelihood of this serious complication. We have never had a PE after a gastric bypass. A “leak” is when intestinal fluid spills out from where the stomach and intestines are connected. This complication can result in peritonitis. This complication occurs in 0.5% of patients in experienced hands. We have not had an anastomotic leak in several years. Leaks can be managed by a number of methods – sometime requiring a re-operation. Bleeding is a complication that requires transfusion in 1 percent of patients. Bleeding rarely requires re-operation. Nausea that lasts for more than several days is uncommon. Rarely nausea lasts for several weeks. Nausea always resolves with a little time. There are numerous potential complications (some serious and some not) that can occur after any operation. A complete listing cannot be anticipated.