Risks of Surgery

What are the Risks of Bariatric Surgery?

The risks of bariatric surgery vary depending upon individual medical history. However, the risks are similar to those of any other abdominal operation.

Some common problems associated with surgery are as follows:

Lung Problems (atelectasis, pneumonia, pulmonary embolus)

  • Atelectasis is a partial collapse of small air passages in the lung. After surgery, the patient's breathing does not fully inflate the lungs and the tiny air passages may not be able to stay open. The best treatment for atelectasis is walking after surgery, performing the cough and deep breathing exercises that are taught before surgery and using the CPAP machine.
  • Pneumonia is an infection in the lungs that can occur when respiratory secretions are not cleared. Pneumonia can be prevented by preventing atelectasis.
  • Deep Vein Thrombosis is a blood clot that can form in the veins of the legs. Both obesity and surgery increase the risk, because the person is less active and blood flow slows, creating the potential to clot. If a clot breaks off and floats through the veins to the lungs, it is called a pulmonary embolism. We try to prevent blood clots by thinning the blood with medications. Special compression stockings are also used to keep the blood flowing faster in the veins. In addition, patients are encouraged to walk beginning the night of surgery to improve circulation.


Wound infections occur in 5 to 10 percent of patients after bariatric surgery. Obese patients have a very deep layer of fat under the skin, which can become infected. Re-opening part or all of the wound treats most infections. While it is an inconvenience, a wound infection is usually not a serious problem.


An abscess is a collection of infected fluid or pus that occurs somewhere in the body. After an abdominal operation, a pocket of fluid may develop. If bacteria are present, the fluid becomes infected, creating an abscess. By draining the infected fluid and providing antibiotics, most abscesses may be treated.

Anastomotic Leak

An anastomotic leak can occur when a complete seal is not formed during the connection from bowel to bowel, or bowel to stomach. Fluid leaks out of the bowel into the abdominal cavity and may cause a serious infection or abscess. Depending on the size of the leak, a second operation may be necessary. Smaller leaks may be treated by inserting a drain. Until the leak seals, the patient is unable to eat or drink. Anastomotic leaks almost always result in a longer hospital stay. There may be discomfort from the drain.

Bladder Infection

A urinary catheter is usually placed during surgery and is left in for the first night. Urinary catheters can lead to a bladder infection, however they are usually easily treated with antibiotics.

Bleeding (Hemorrhage)

Whenever surgery is performed, blood vessels must be cut. Tying vessels (with a piece of thread) or stitch stops bleeding. Electrocautery is also used to create a clot at the tip of the blood vessel. Sometimes, a vessel may begin to bleed again, either inside the abdomen, or in the skin. Bleeding is usually controlled without having to go back to the operating room.


  • Bowel Obstruction
    After any abdominal surgery, scars or adhesions may form. The bowel may become kinked around an adhesion and blocked. This is called a bowel obstruction and another surgery may be needed.
  • Anastomotic Stricture
    During gastric bypass surgery, the opening that allows food to leave the stomach is purposely made very small. As healing scars form, the opening between the stomach and bowel may become too small to allow food to pass through. This problem occurs in 5 to 10 percent of cases and can be treated on an outpatient basis.

Nutritional Problems

Nutritional problems are rare after bariatric surgery if the patient follows the instructions of the surgeon. Nutritional problems are avoided by taking the proper vitamin and mineral supplements and eating a healthy diet. A dietitian is always available to work with you. The most common nutritional deficiencies and eating difficulties are described below:

  • Protein Deficiency
    A constant supply of protein is needed to keep the body's tissues in good health. Because gastric bypass reduces stomach volume, additional protein-rich foods must be eaten, preferably at the beginning of every meal.
  • Vitamin and Mineral Deficiency
    After bariatric surgery, patients will not be able to eat enough food to meet recommended vitamin and mineral requirements. A high potency multivitamin/mineral supplement must be taken daily. In addition, daily calcium, B12 and iron supplements are also recommended to maintain adequate vitamin and mineral stores and prevent anemia and osteoporosis.
  • Nausea and Vomiting
    After gastric bypass surgery, vomiting will result if the patient continues to eat after feeling full. Most patients experience this until they learn to eat slowly, chew food well and avoid that last bite when fullness occurs. By waiting just a few minutes, a feeling of satisfaction occurs and the desire to eat more is lost.
  • Food Intolerance
    Red meat is not well tolerated after surgery. Patients should avoid red meat for three to four months after surgery. After gastric bypass surgery, a condition called "dumping syndrome" may occur. Lightheadedness, profuse sweating, rapid heart rate, cramping abdominal pain, nausea and diarrhea may occur. The problem can be prevented by avoiding sweets; fried, fatty or greasy foods; eating too much at one meal; or drinking fluids with meals.

To register for a free informational seminar or to make an appointment for a consultation with a bariatric surgeon at Jeanes, click here or call 215-728-CARE (2273).


Jeanes Hospital Blood Drive
Help save lives by donating blood on January 23. read more»
Jeanes Hospital Named America’s 100 Best Hospitals for Cardiac Care for Three Years in a Row
New report identifies Jeanes among the top hospitals nationally for excellence in cardiac care, cardiac surgery, and gastrointestinal care. read more»
The Orthopaedic Center at Jeanes Presents: Total Joint Replacement Classes
Upcoming 2019 Class Schedule read more»