Potential Risks/Side Effects of Bariatric Surgery

Like all surgery bariatric surgery has some potential risks. The complications are a factor of how ‘high risk’ a patient you are and the experience of the medical team taking care of you. The major risks that can lead to death are pulmonary embolus (blood clot to the lungs) and peritonitis (infection in the abdomen) from a leak from any of the hook-ups between pieces of intestine or to the pouch. Most of the other side effects are not life threatening and can be treated easily.

Potential Risks Post Surgery

• Leaks from Staples or Sutures: There may be leakage of fluid through the staples or sutures from the stomach or intestine which results in abdominal infection. This is a plausible (but rare) risk which usually requires an operation.

• Infection from Wounds: May require long term treatment (sometimes months) with dressing changes, but treatment can be managed without further surgery.

• Blood Clots: A blood clot to the lungs or pulmonary embolism which most commonly results from deep vein thrombosis (a blood clot in the deep veins of the legs or pelvis) that breaks off and migrates to the lung, a process termed venous thromboembolism , is a possible complication after surgery and can be very serious. Blood clots can usually be prevented with blood thinning drugs

• Incisional hernia: This is a result of vigorous physical activity soon after the bariatric surgery where a weakness or flaw in the incision after an operation may allow intestine or tissue to swell through. This can be prevented by avoiding strenuous physical activity for atleast 2 months (such as lifting heavy items or weights or heavy housework should be avoided) post surgery.

• Ulcers: A rare complication of gastric bypass surgery is an ulcer developing where the small intestine attaches to the upper part of the stomach. Patients who smoke or take aspirin or nonsteroidal anti-inflammatory agents are at an increased risk of developing ulcers.

• Gallstones: commonly occur with rapid weight loss. Up to 50% of patients generally develop gallstones after gastric bypass surgery and these are usually harmless. However, gallstones can cause nausea, vomiting, and abdominal pain, requiring surgery.

Some of the other side effects of bariatric surgery are as follows

• Nausea & Vomiting: Patients may experience a few bouts of nausea or discomfort in the abdominal area after surgery as they are getting used to their new diet. This usually occurs due to eating too quickly or taking large bites of food and not chewing enough before swallowing. Foods that are dry or tough should be avoided. Continuous vomiting or vomiting accompanied by abdominal pain requires immediate medical attention

• Constipation: is quite common after bariatric surgery, patients may experience smaller and fewer bowel movements. Taking a fibre supplement or laxatives may be advised if symptoms continue to exist

• Dehydration: Dehydration can lead to nausea and vomiting and vitamin deficiency. It is advised to drink at least 2 litres of liquid per day during the first few months post the surgery though patients may find it difficult to consume this amount of fluid.

• Vitamin Deficiency: Due to the bypass of the stomach and duodenum, there could be iron, vitamin B12 and other micronutrient deficiencies after standard gastric bypass. This can be managed by daily supplements of multi vitamin, vitamin B12, calcium and iron.

• Gastric Dumping Syndrome: Gastric dumping syndrome or rapid gastric emptying is a condition where ingested foods bypass the stomach too quickly and enter the small intestine largely undigested. This occurs due to consumption of high calorie foods such as sweets and greasy fried foods. To avoid gastric dumping patients should avoid sugary and fatty foods post surgery.

• Intolerance to certain foods: Patients may be intolerant to certain foods after the surgery. Eating in smaller portions and eating food slowly and chewing well before swallowing can substantially reduce problems with food intolerance. Foods such as fresh bread, pasta and rice should be avoided as they become sticky and gooey and cause blockage in the stomach pouch outlet. Foods that are dry and tough (meats, steaks, pork etc) should be avoided. Vegetables that cause gas should be avoided.

• Cold Sensitivity: Due to weight loss patients may feel colder than usual. This is due to the change in metabolism and a loss in body fat. 

• Temporary Hair Thinning: About 50% percent of the women who undergo bariatric surgery notice hair thinning; this is temporary and can be reduced by sufficient intake of multivitamins, protein, zinc and biotin supplements.

• Fertility & Child Birth: Most obese women have problems related to fertility and irregular menstrual cycles. Due to weight loss after the surgery women get regular periods and become more fertile. Nutritional deficiencies and rapid weight loss can harm the developing foetus which can lead to birth defects.