The development of gallstones is related to the rapid and significant amount of weight loss and therefore is highest in the first six months after surgery. Gallstones are not a complication of surgery as such, but rather a complication of rapid weight loss. Obese persons have a very high rate of gallstone formation compared to normal weight persons. By age 50, nearly 50 % of morbidly obese women have developed gallstones.

Bowel obstruction due to a blockage from adhesions (scar tissue) can occur as it can after any abdominal operation, trauma or intra-abdominal infection.

Stomal ulcer is an acid-peptic ulcer that occurs on or near the anastomosis (connection) between the stomach pouch and the bowel, “the stoma”. An ulcer may also rarely occur in the usual duodenal ulcer position. There is a higher risk of developing ulcers after bariatric surgery. Patients who use non-steroid anti-inflammatory drugs (NSAID) such as ibuprofen, Aleve®, etc., and smokers have a even higher incidence of ulcers. For this reason, all bariatric patients are instructed to avoid the use on all anti-inflammatory medications containing ibuprofen (i.e. Advil®, Nuprin®, Haltran®, Midol®, Motrin®, Aleve®, etc.) after surgery and for life. Ulcers can also lead to erosion of the Lap-band® into the stomach wall.

Stomal ulcer is an acid-peptic ulcer that occurs on or near the anastomosis (connection) between the stomach pouch and the bowel, “the stoma”. An ulcer may also rarely occur in the usual duodenal ulcer position. There is a higher risk of developing ulcers after bariatric surgery. Patients who use non-steroid anti-inflammatory drugs (NSAID) such as ibuprofen, Aleve®, etc. and smokers have an even higher incidence of ulcers. For this reason, all bariatric patients are instructed to avoid the use on all anti-inflammatory medications containing ibuprofen (i.e. Advil®, Nuprin®, Haltran®, Midol®, Motrin®, Aleve®, etc.) after surgery and for life. Ulcers can also lead to erosion of the Lap-band® into the stomach wall.

Late stomal stenosis, or narrowing of the outlet of the stomach pouch, is a complication that can occur in gastric bypass patients. Re-operation may be necessary to correct this.

Iron deficiency anemia is a complication of significance in the long term. It usually occurs in menstruating women who do not take extra iron supplements. It is almost always preventable. It is not difficult to treat, but must be recognized in order for it to be treated. This is one of the important reasons for long-term follow-up.

Lactose intolerance results from the body's inability to digest the cow milk sugar called lactose. Gastric bypass surgery can unmask lactose intolerance, but not cause it. Lactose is commonly found in dairy-based foods and beverages, and is digested in the intestines by the enzyme lactase. Lactase breaks down lactose so it can be absorbed in the blood stream. When the body does not produce enough lactase, lactose cannot be digested,which may result in lactose intolerance.

Depending on the individual, the symptoms may include cramping, diarrhea, bloating, gas and nausea. If you experience these symptoms after eating dairy products, you may be lactose intolerant.

Products that contain large amounts of lactose are cow milk and ice cream; smaller amounts of lactose are found in yogurt, cottage cheese and hard cheese. Prepared foods can also contain lactose. You will need to look on food labels or ingredient listings for whey, lactose, non-fat milk solids, buttermilk, malted milk, margarine and sweet or sour cream. Some breads, dry cereal and instant soups contain small amounts of lactose. Although there are supplements that you can take, elimination of dairy is the best approach to solving the problems associated with lactose intolerance. You can still enjoy goat milk products without any worry of having lactose intolerance, or Lactaid® and soymilk.

Dumping Syndrome
Under normal physiologic conditions, the stomach and pylorus (the opening of the stomach into the small intestine) control the rate at which the gastric contents leave the stomach. That is, the stomach, pancreas and liver work together to prepare nutrients (or sugar) before they reach the small intestine for absorption. The stomach serves as a reservoir that releases food downstream only at a controlled rate, avoiding sudden large influxes of sugar. The released food is also mixed with stomach acid, bile and pancreatic juice to control the chemical makeup of the food that goes downstream and avoid the "dumping syndrome."

“Dumping syndrome” occurs with the Roux-en-Y Gastric Bypass patient only and is divided into early and late phases.

Dumping syndrome occurs with the Roux-en-Y Gastric Bypass patient only and is divided into early and late phases.

“Early dumping syndrome” happens when the lower end of the small intestine (jejunum) fills too quickly with undigested food from the stomach. Patients can develop abdominal bloating, pain, vomiting and vasomotor symptoms (flushing, sweating, rapid heart rate, light headedness). Other patients may have diarrhea. Since with the Roux-en-Y Gastric Bypass the majority of the stomach is not being used and a new, small pouch that directly connects to the small intestine is created, there may be “dumping”. “Early dumping syndrome”e is due to the now-rapid gastric emptying causing bowel distension plus movement of fluid from the blood to the intestine to dilute the intestinal contents. These symptoms usually occur 30 to 60 minutes after eating.

“Late dumping” is related to the blood sugar level. The small bowel is very effective in absorbing sugar, so that the rapid absorption of a relatively small amount of sugar can cause the glucose level in the blood to rise rapidly. The pancreas responds to this glucose challenge by increasing the insulin output. Unfortunately, the sugar that started the whole cycle was such a small amount that it does not sustain the increase in blood glucose, which tends to fall back down at about the time the insulin surge starts. These factors combine to produce hypoglycemia (low blood sugar) which causes the individual to feel weak, sleepy and profoundly fatigued.

Restricting simple carbohydrates (rice, pasta, potatoes and other sweet tasting foods), eating more protein and not drinking liquids during a meal can reduce the symptoms of “dumping”. Further, avoid foods that are very hot or very cold, which can also trigger symptoms.

Obviously, surgeons consider “dumping syndrome” to be a beneficial effect of Gastric Bypass surgery. It provides a quick and reliable negative feedback to eating the “wrong” foods. In practice, most patients do not experience full-blown symptoms of “dumping” more that once or twice. Most simply say that they have lost their taste for sweets.

Be aware that “late dumping” is the mechanism by which sugar intake can create low blood sugar, and it is also a way for patients to get into a vicious cycle of eating. If the patient takes in sugar or a food that is closely related to sugar (simple carbohydrates like rice, pasta, potatoes) they will experience some degree of hypoglycemia in the hour or two after eating. The hypoglycemia stimulates appetite and the patient will want to eat again.