Gastric bypass surgery is one of the bariatric surgical procedures for reduction of stomach volume. It is generally advised for people whose Body Mass Index is above 35, who don't respond to conventional diet and exercise and now face life threatening health risks. But this method of weight loss comes with its own set of problems and about 10-20 percent people have to go in for follow-up surgery to correct the complications due to the original surgery. Some complications are enumerated below. One must discuss all possible options and side effects with the surgeon before taking on this procedure.

Post-surgery Pulmonary Embolism is a situation where there is a one percent chance of blood clots developing in the legs. But there are some techniques available that do prevent this problem like the use of surgical compression stockings that put pressure on the legs and ensure that blood flow is maintained after surgery. But in a situation where the clots have formed they may break off and get carried into the lungs, where they can get caught and then emergency surgery is required.

Post-surgery Peritonitis is a condition where a staple or suture used during surgery ruptures and stomach fluid leaks into the abdominal cavity. The ensuing infection is called peritonitis which is a serious condition. Emergency surgery to seal the leak and a course of antibiotics to kill the infection is called for in such a case.

Post-surgery Gallstones are caused by rapid weight loss. If gallstones exist before the operation then the surgeon will remove the gall bladder during the operation to prevent further complications. Generally medication is administered to avoid problems developing after this kind of surgery.

Post-surgery Chronic Vomiting happens because the connection between the stomach and the intestines narrow as a result of scar tissue forming. When food cannot pass easily, there tends to be vomiting after eating. During follow-up surgery, the doctor inserts a balloon into the opening and stretches it. It is an outpatient procedure and has a 90% success rate.

Post-surgical Dumping Syndrome occurs when food moves too fast through the small intestine and causes nausea, weakness, sweating, faintness, and possibly diarrhea soon after eating. Highly refined foods like sugar are known to cause this problem. Maintaining a proper diet can control and prevent this from happening. .

Post-surgery Nutritional Deficiencies like anemia, osteoporosis, and metabolic bone disorders are common occurrences. Dietary supplements and professional help from a dietician to ensure there is no nutritional deficiency generally helps.

Post-surgery Stomach Ulcers develop on top of the intestine when it is connected to the new stomach pouch. This is generally treated by traditional ulcer treatments.

Post-surgical Hernia develops in parts of the abdominal muscles at a weak point that allows a part of the stomach or intestines to push through. This can be corrected through surgery.

Pregnancy is something that women should avoid for at least two years after surgery to prevent serious post-surgical complications. A pregnant woman has to take the correct nutritional supplements to protect both her and the baby from developing nutritional deficiencies.

Post-surgical Bowel Obstruction results when the scar tissue develops at the place where the stomach was sewn or stapled to create a smaller pouch. Immediate emergency medical treatment that may include surgery is called for.