Gastric Bypass Side Effects

As with any surgery, the side effects of gastric bypass surgery can range from minor to severe. Before undergoing this surgery, it’s important to know what some of these side effects might be.

Even though it may improve your quality of life, gastric bypass surgery can affect your digestive tract.

Adherence to your specific eating plan and regular exercise pre- and post-gastric bypass is critical. This is to avoid complications and ensure your long-term health and weight management. 

The overall risk of gastric bypass side effects should not outweigh your risk of ongoing obesity. 

This article provides a thorough overview of gastric bypass surgery side effects. We also aim to inform you of the short and long-term complications, as well as other risks of gastric bypass.

 

Side Effects of Gastric Bypass Surgery

Most Common Gastric Bypass Side Effects

Includes: Nausea and vomiting, dysphagia, constipation, stomach bloating, and dehydration. Fecal and urinary incontinence has also been documented, making it difficult for you to pass stools and urinate properly. 

With inconsistent dietary adherence, the stomach can stretch to compensate for the additional food being taken in. This will lead to unnecessary and unhealthy weight regain, which is a severe drawback and waste of your gastric bypass.

Less Common Gastric Bypass Side Effects

gastric bypass surgery side effects

This includes an anastomotic leak, peritonitis, bowel obstruction, gastrointestinal tract hemorrhage, epigastric pain, and stricture. 

The anastomotic leak happens when leakage occurs at the staple line or connection between the stomach and intestine. It is a dangerous and life-threatening complication. It may cause bleeding and infection. 

Leakage symptoms may include: increased heart rate (tachycardia), fever, decreased urine output, pain in your stomach and the left shoulder, and low blood pressure.

Peritonitis can be a serious complication of gastric bypass. It occurs when an anastomotic leak causes inflammation of your abdominal membrane lining, called the peritoneum. Signs and symptoms of peritonitis may include fever, severe gastric pain and back pain, pelvic pressure, hiccups, tachycardia, and restlessness. 

Small Bowel Obstruction (SBO) is generally due to internal hernias, adhesions, and strictures. Patients may present with abdominal pain or cramps, with or without vomiting. 

Stenosis or stricture can occur due to the narrowing of the opening between your stomach and intestine post-op. This can cause vomiting after eating or drinking. 

Severe Gastric Bypass Side Effects

  • Excessive bleeding
  • Infection
  • Leakage in the gastrointestinal tract

Short-term Side Effects of Gastric Bypass

Early complications after gastric bypass surgery may include nausea, vomiting, diarrhea, constipation, food intolerance, dizziness, and general fatigue that may be easily treated.

Long-Term Side Effects of Gastric Bypass

Long-term complications of an anastomotic leak may include ulcers, scarring, and anastomotic stricture. 

Anastomotic Stricture causes progressive dysphagia and vomiting. 

A fistula, an abnormal drainage tract, could also develop. Gastro-gastric fistula (GGF) usually causes weight gain.

Gastric bypass complications years later may also include bowel obstruction, hernias, and vitamin and mineral deficiency, . 

Blood clots, Deep Vein Thrombosis (DVT), Pulmonary Embolism, Lung or breathing problems can be a risk in the long-term. 

Pneumonia or Aspiration Pneumonia is another dangerous complication, resulting from digestive juices entering into the lungs.

Gastric bypass side effects in the COVID-era could be potentially even more life-threatening, as any form of contamination could cause sepsis and exacerbate your situation.

Mortality rates post gastric bypass are low, but can be possible. 

Dumping syndrome occurs when food enters moves from the stomach to the small intestine too quickly (‘dumped’) without being digested. It can lead to symptoms like nausea, vomiting, bloating, abdominal cramps, diarrhea, low blood sugar (hypoglycemia), and malnutrition. Further side effects such as fatigue, dizziness, tremors, and altered mental state may occur.

 

Malnutrition and Nutrient Deficiencies

gastric bypass side effect

Gastric bypass is a restrictive and malabsorptive surgical procedure. This can give rise to nutritional deficiencies - specifically Iron, Vitamin B12, and Vitamin D deficiencies. 

Iron deficiency is the most common. It can occur after any bariatric procedure, despite preventative supplementation. The prevalence rate can range from 3 months to 10 years after surgery. This can occur due to malabsorption, decreased stomach acid, and other supplements. Patients may present with generalized weakness and microcytic anemia. 

Vitamin B12 deficiency often presents as asymptomatic 2-5 years post weight loss surgery. However, it may lead to megaloblastic anemia and neurological symptoms (neuropathy) such as memory problems, unsteady gait, and depression.

The prevalence of vitamin D deficiency is 100%. Routine screening is recommended because deficiency may lead to osteoporosis.

Vitamin B9/folate/folic acid deficiency can also result in megaloblastic anemia and even paranoia. This deficiency is seen in up to 65% of bariatric patients. 

Vitamin B1/Thiamine deficiency is one of the most serious vitamin deficiencies post gastric bypass. Patients may present with dry or wet beriberi, heart problems, Wernicke’s encephalopathy, and headaches. If symptoms go untreated, there can be irreversible damage to the body. 

Calcium deficiency further leads to an increase in parathyroid hormone (PTH). This causes osteopenia and osteoporosis. 

Vitamin C and minerals such as Zinc, Copper, and Selenium deficiencies may also occur.

 

Gastric Bypass Anatomical Side Effects

  • Gastric bypass side effects also include stomach ulcers. This can be very serious, with excruciating pain, anemia, or bleeding
  • Marginal ulceration is characterized by peptic ulcers at the anastomotic site. Complications of it are serious and include perforation, bleeding, and stricture 
  • Mucosal ischemia may also occur. This can promote the relocation of bacteria and toxins in the gut
  • Foreign body reactions to staples and sutures during and post-op also may occur
  • Staple-line failure in the stomach pouch

side effects of gastric bypassThe risk of Gallstones (Cholelithiasis) increases with rapid weight loss. Choledocholithiasis happens when gallstones lodge and block your common bile duct. This could further lead to gallbladder inflammation (cholangitis) or even pancreatitis. Some cases may be so severe that cholecystectomy may be needed.

Hair loss after gastric bypass is also a common complaint due to stress of surgery, malabsorption, malnutrition, deficiencies, and inflammation. 

Hypoglycemia can occur and may be related to unhealthy eating, malnutrition, dumping syndrome, or hormonal changes. It can cause dizziness and fatigue.

 

Other Side Effects of Gastric Bypass Surgery

  • Excess loose or sagging skin on your tummy, arms, and thighs, including over your breasts may require post-bariatric plastic surgery
  • Psychological distress and depression after bariatric surgery may be due to the huge adjustment in eating habits and social relationships
  • While bariatric surgery may help to improve thyroid functioning in hypothyroid bariatric patients, thyroid problems after gastric bypass may occur 

 

Final Words

As with any surgery, bariatric surgery comes with surgical and nutritional risks. However, the benefits of surgery likely exceed the risks. Many look forward to improvements in medical conditions and overall health. This includes extreme weight loss and increased reproductive function. 

Lifestyle change is required for life in order to minimize the complications and risks of bariatric surgery. Following a healthy diet high in protein and consistently taking a bariatric specific multivitamin will aid in healing and restoration. 

Protein intake will also be essential for minimizing malnutrition. If you are not getting adequate amounts through dietary intake, there is protein power for gastric bypass available to compensate for what you are lacking in the diet. 

Weight regain post-op is an unfortunate and dangerous complication. This is what usually causes negative side effects of gastric bypass surgery. All efforts should be made on your part to avoid weight regain. 

A healthy meal plan with multivitamins and minerals, and regular exercise is key. Unhealthy living and non-steroidal anti-inflammatory drugs should be avoided to prevent complications.

Complex revision procedures are available to correct your original gastric bypass when faced with side effects. However, you will still have to put in the effort in order to experience the benefits of any bariatric surgery.

 

**This blog is for information and education purposes only. This information is not intended to substitute professional medical advice, diagnosis, or treatment. Please consult with your physician or another qualified health provider with any questions in regards to a medical condition.