As with any major surgery, there are risks with gastric bypass surgery. While the typical gastric bypass patient will not have complications after surgery, it is important that you understand the risks before undergoing surgery.  Talk to your surgeon or health care provider about any concerns you might have.

Bariatric surgery side effects include:

  • Chronic nutritional problems
  • Protein deficiency
  • Vitamin and mineral deficiency
  • Transient hair loss
  • Muscle mass loss
  • Nausea/vomiting
  • Dumping syndrome
  • Red meat intolerance
  • Alcohol intolerance
  • Lactose intolerance
  • Changed bowel habits
  • Excess skin
  • Growth of gallstones

Laparoscopic Gastric Bypass

Laparoscopic Sleeve Gastrectomy

  • Because the duodenum is bypassed, poor absorption of iron and calcium can result in the lowering of total body iron, which may result in iron deficiency anemia. Metabolic bone disease has also occurred in some patients. These can be managed through proper diet and vitamin supplements.
  • Chronic anemia due to Vitamin B12 deficiency may occur. This problem usually can be managed with Vitamin B12 pills or injections.
  • A condition known as "dumping syndrome" can occur as the result of rapid emptying of stomach contents into the small intestine. This is sometimes triggered when too much sugar or large amounts of food are consumed.


  •    Some people with a gastric band develop a food intolerance resulting in symptoms such as nausea, vomiting and gastro-oesophageal reflux
  • There is a risk that over time your band may slip out of position and your stomach pouch will become enlarged.

Although there are many benefits of gastric sleeve surgery, there are also potential risks. Your chances of developing a problem from a gastric sleeve procedure are small. However, they do sometimes occur. Here are a few of them:

  • Organ Damage– Nearby organs can be punctured or otherwise damaged during the surgery.
  • Gastric Inflammation– The lining of your stomach could be irritated or inflamed by the procedure.
  • Chronic Heartburn– You can have regular episodes of heartburn due to the reduction in the size of your stomach.
  • Infections– Partially digested material could leak from the surgical wound into the gut and cause infections.
  • Scarring– Your digestive tract could develop scarring from the surgery.
  • Reflux– Acid moving up from the stomach into the esophagus causing burning chest pain. This condition occurs in roughly 20% of all sleeve patients.
  • Vomiting– Uncontrollable vomiting may occur after consuming a large quantity of food.