Typical risks associated with weight loss surgery include:

• Vomiting from eating too much too quickly and not chewing well;

• Constipation;

• Nutritional deficiencies such as anemia and osteoporosis.

As with any surgery, wound infections can occur up to three weeks after surgery. These can be treated with antibiotics, and sometimes require further surgery.

Complications that may develop following weight loss surgery include: 

• Hernia;

• Gallstones;

• Ulcerations;

• Gastric prolapse;

• Severe scarring of the new stomach pouch;

• Excess skin that may need to be removed in an additional surgery;

• Dehydration;

• Hair loss;

• Kidney stones;

• Hypoglycemia.

Rare but serious complications include:

• Bleeding in the stool, or black stools;

• Leaks in new connections made by weight loss surgery; these usually occur within five days of surgery;

• Blood clots in the lungs, called pulmonary emboli, rarely occur, but if they do, they are the most common cause of death after weight loss surgery. Blood clots can be usually prevented with blood-thinning medicines and frequent activity;

• Blood clots in the legs, called deep vein thrombosis, or DVT;

• Pneumonia.