Gastric Bypass Complications

Certain complications are seen during the early postoperative periods while others may present weeks to months following the surgery.

  1. Mortality (death) has been reported at approximately 0.13% for laparoscopic gastric bypass. Leaks were responsible for approximately 50% of the deaths and pulmonary embolus was the cause at approximately 30%.
  2. Bleeding both during and immediately after surgery. Bleeding after gastric bypass has been reported in 0.6 to 4.0% of patients. If bleeding occurs, a transfusion of blood products may be necessary. Surgery is reserved for continued bleeding or severe bleeding.
  3. Infections can occur after surgery including lung infections, incision site infections or internal staple lines (anastomosis lines). These infections may only require antibiotics, but surgery may be required depending upon the type and degree of infection. Wound infections have been reported to occur between 3 to 4%. Pre-operative antibiotics are used to reduce wound infections. Signs of wound infections include unexplained fevers, redness (erythema), or drainage.
  4. Blood clots can form in blood vessels during or after surgery. A blood clot can develop in the leg called a deep vein thrombosis (DVT). A blood clot that travels is called an embolus. Pulmonary embolism (PE) remains one of the leading causes of early mortality following gastric bypass. The use of heparin, pneumatic compression boots, and early post-operative walking are techniques used to prevent PE and DVT.
  5. Leaks may occur anywhere the stomach or small intestine is re-connected (anastomosis). If a leak happens, it must be treated right away. Re-operation may be needed to fix the leak. Leaks from gastrointestinal tract are another major cause of post-operative mortality. The chance of a leak occurring after gastric bypass surgery has been reported to be between 0 and 5.1%. Early symptoms of a leak are low-grade fevers, difficulty breathing, or an unexplained increase in heart rate. The concern is that a severe infection called sepsis is occurring. An exploratory surgery may be necessary without delay.
  6. Malnutrition, dehydration, or anemia. Malnutrition occurs when your body is not receiving enough nutrients, like iron, protein, vitamins, and minerals. Following the recommendations regarding food choices and vitamin supplements is extremely important. Dehydration occurs when you are not drinking enough water. Anemia causes you to feel very tired, and weak, and you may become pale because fewer red blood cells are available to carry oxygen. You need to take iron supplements as recommended. Further information is provided in this education booklet about prevention of malnutrition.
  7. Marginal Ulcer may occur at the edges of your stomach pouch where the staple line exists. A marginal ulcer destroys the inner lining of the small intestine that is adjacent to the stomach pouch.  This can cause bleeding, pain, and can even result in perforation.  Irritants that have been shown to lead to a marginal ulcer are the following:  tobacco, steroids (such as Prednisone), anti-inflammatory drugs (such as aspirin and ibuprofen), caffeine or alcohol. Marginal ulcers have been reported to occur in up to 13% of gastric bypass patients.  Eliminating the irritant and taking prescribed medications can usually heal the marginal ulcer, but sometimes surgery is necessary. Smoking is a major cause of marginal ulcers and you must not re-start smoking after surgery at anytime. Ulcers may occur years after the bypass surgery. 
  8. Blockage of the small intestine prevents food or liquids from passing through the intestines. The blockage can be caused by scar tissue (adhesions) that narrows or totally blocks the intestines. You may feel nauseous, have abdominal pain, or vomit. In some cases another operation may be needed.
  9. Hernias occur because a portion of the intestine is pushing outward due to a weakness of the abdominal wall. Ventral incisional hernia and internal hernia are the two different types of hernias. An internal hernia can occur after gastric bypass surgery because of the re-routing of the small intestine. The location of the internal hernia is associated with the internal spaces through which herniation of the small intestine can occur. The incidence of an internal hernia has been reported to be 1 to 5%. Severe pain and vomiting resulting from a strangulating internal hernia will require immediate surgery. Hernias may present years after the surgery.
  10. Gallstones may form in the gallbladder causing the tube coming out of the gallbladder to be blocked by the stones. Rapid weight loss increases the development of gallstones. Removal of a person’s gallbladder is not routinely recommended at the time of gastric bypass surgery.
  11. Stomal stenosis or stricture is a narrowing at the bottom of the stomach pouch that prevents food from leaving the stomach pouch easily. Stomal stenosis typically occurs several weeks after surgery with symptoms of nausea, vomiting, dysphagia (difficulty swallowing), reflux, and inability to tolerate food or fluids. Stomal stenosis has been reported in 6 to 20% of patients who have laparoscopic gastric bypass surgery. An endoscopy or an upper gastrointestinal series is used to determine if a stomal stenosis has developed. An endoscopic balloon is used to stretch (dilate) the narrowing at the bottom of the stomach pouch. Repeat dilatations may be required for some patients.

Long-Term Considerations with the Gastric Bypass

Vitamins & Minerals taking your vitamin & mineral supplements is mandatory for the rest of your life. As malabsorption directly impacts the body’s ability to absorb certain vitamins and minerals from food. Gastric Bypass patients will need a multivitamin, calcium citrate with vitamin D, B12, and iron. The bariatric surgeons office will provide to you very specific details about the amount of each supplement you will need and the best form of supplement to ensure absorption. You must have your blood work monitored along with taking these supplements for the rest of your life!

Dumping Syndrome happens because of the physical changes made to the stomach and small intestine at the time of gastric bypass surgery. Before surgery, the stomach adds specific juices to help break down foods along with controlling how fast food leaves the stomach and enters into the small intestine. After gastric bypass surgery, those special juices are not available and the food enters into the small intestine quickly. Dumping syndrome is most commonly caused by simple carbohydrates, i.e. sweets and juices. Symptoms of the dumping syndrome are abdominal bloating, pain, vomiting, flushing, sweating, rapid heart rate, lightheadedness, and/or diarrhea.

Nausea or vomiting can be caused by eating too fast, not chewing food properly, eating food that is too dry, eating too much food at once, drinking liquids with meals or right after meals, drinking with a straw, or lying down too soon after a meal. It may be very difficult at first to realize how little food will satisfy your hunger.

Lactose intolerance is the body’s inability to digest cow milk sugar called lactose.   It is common in adults, particularly among those of Asian and African descent.  Gastric Bypass surgery does not cause lactose intolerance, but can make the symptoms worse for those that have lactose intolerance.   Lactose is found in dairy based foods and beverages, and is digested in the intestines. Symptoms of lactose intolerance may include diarrhea, cramping, gas, or bloating.

Bowel habits will change for a period of time after surgery. You may have one to three bowel movements a day. Foul smelling gas may also occur. Most of these changes resolve as your body heals and your body gets use to the changes.

Some patients will have loose/frequent bowel movements in the first 2-4 weeks post op. The number of bowel movements may range from 2-6 each day. This is normal and the frequency will come close to "normal" after about 4 weeks.  Your new "normal" will be to have a bowel movement 2-3 times per week.  This new "normal" is the result of the small amount of food that you now eat.  Many patients will have a problem with constipation.  This happens because of dehydration (not drinking enough) and can be avoided if you drink the recommended 64 ounces (2 liters) of fluid each day.  A diet low in fiber may be a factor as well, and fiber powders may be used to increase your daily fiber intake. Additional fiber can be obtained from products such as Citrucel, Benefiber, Fibersure, or Metamucil.

Hair loss/skin changes may occur after rapid weight loss and are temporary. During rapid weight loss caloric intake is much less than the body needs, and protein intake may be low. Hair loss or thinning usually occurs anywhere from 3 to 9 months after surgery. The skin texture and appearance may change. It is not uncommon to develop acne or dry skin. Protein, vitamins and minerals, essential fatty acids and water intake are all very important to avoid these problems.  Biotin tablets have shown to be helpful for some patients.