Gastric bypass is a type of weight-loss surgery. During the surgery, the top of the stomach is changed into a small pouch. A loop of your small intestine is cut, and one end of the loop is connected to the stomach pouch. The other end of the small intestine loop is connected lower down on the small intestine. Each of these connections is called an anastomosis.

One risk of a gastric bypass is digestive juices and partly digested food leaking through an anastomosis. This is a serious complication after gastric bypass surgery. A leak may happen up to several weeks after surgery. Most occur within a few days after surgery.

The cause may vary from person to person. It may be caused by a problem with the tool or materials used to close the anastomosis during surgery. It may be because of problems with the blood flow in the area after surgery. Or it may be linked to other reasons for poor wound healing, such as diabetes or smoking.

The more obese you are before surgery, the more at risk you are for a leak. You are also more at risk for this problem if you:

• Have other health problems
• Have complications during surgery, or a prolonged surgical time

Symptoms can occur a bit differently in each person. They can include:

• Fast heart rate
• Fever
• Chills
• Stomach pain
• Chest pain
• Shortness of breath (rapid breathing or difficulty breathing)
• Fluid leaking from an incision site
• Nausea and vomiting
• Pain in the left shoulder area
• Low blood pressure
• Less urine
• General feeling of discomfort (malaise)

The symptoms of anastomotic leaking after gastric bypass surgery may look like other health conditions. See your doctor for a diagnosis.

Your doctor will ask about your symptoms and give you a physical exam. You may also have imaging tests, such as an upper GI (gastrointestinal) series or a CT scan. For either test, you will drink a liquid called a contrast dye. This helps the images show up easier. A machine will scan you with X-rays and create images. The images can show if the dye is leaking through the anastomosis.

If the imaging test does not show leaking but you still have symptoms, your doctor may advise an emergency surgery to look for a leak.

The leak needs to be treated right away. Your health care team will likely:

• Give you antibiotics through an I.V. (intravenous line).
• Drain any infection caused by the leak.
• Repair the leak, or make a new anastomosis with a second surgery.
• Do an upper endoscopy to place a short-term (temporary) small tube called a stent across the leaking area. This is done from the inside of the gastric pouch or the small intestine.
• Stop all food by mouth. You may be fed through a tube that goes directly into your intestine until the leak has healed.

Talk with your doctors about the risks, benefits, and possible side effects of all treatments.

A leak is serious and can be life-threatening. A leaking anastomosis may cause bleeding and infection until it's treated. Long-term complications may include:

• Sores (ulcers)
• Scarring
• Narrowing of the anastomosis (stricture or stenosis)
• A tunnel (fistula) forming through tissue between the gastric pouch and the bypassed stomach
• Aspiration pneumonia from digestive juices that can spill into the lungs

Contact the doctor if you have:

• Fever (oral) of 100.4°F (38°C))
• Belly (abdominal) pain or left shoulder pain
• Symptoms that don't get better, or get worse
• Nausea or vomiting

• During a gastric bypass, a loop of your small intestine is cut and connected to the stomach pouch. The other end of the small intestine loop is connected lower down on the small intestine. Each of these two connections is called an anastomosis.
• One risk of a gastric bypass is digestive juices and partly digested food leaking through an anastomosis. This is a serious complication after gastric bypass surgery.
• A leak may happen up to several weeks after surgery. Most occur within a few days after surgery.
• You may have an imaging test, such as an upper GI series or a CT scan. Your doctor may advise an emergency surgery to look for a leak.
• A leak is serious and can be life-threatening. A leaking anastomosis may cause bleeding and infection until it is treated. It can also cause long-term complications.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours and on weekends and holidays.