is also affected by the experience of the operating surgeon: the learning curve for laparoscopic bariatric surgery is estimated to be about 100 cases. Supervision and experience are important when selecting a surgeon, as the way a surgeon becomes experienced in dealing with problems is by encountering and solving them. Complications of abdominal surgery Infection Infection of the incisions or of the inside of the abdomen (peritonitis, abscess) may occur due to the release of bacteria from the bowel during the operation. Nosocomial infections, such as pneumonia, bladder or kidney infections, and sepsis (blood-borne infection) are also possible. Effective short-term use of antibiotics, diligent respiratory therapy, and encouragement of activity within a few hours after surgery can reduce the risks of infections. Venous thromboembolism Any injury, such as a surgical operation, causes the body to increase the coagulation of the blood. Simultaneously, activity may be reduced. Gastric Bypass Surgery is done with minimally invasive techniques(laparoscopy). Due to insufflation of the abdominal cavity with CO2 for the surgery the venous return is diminished and this willl lead to deep vein thrombosis of the lower extremities.There is an increased probability of the formation of clots in the veins of the legs, or sometimes the pelvis, particularly in the morbidly obese patient. A clot that breaks free and floats to the lungs is called a pulmonary embolus, a very dangerous occurrence. Blood thinners are commonly administered before surgery to reduce the probability of this type of complication. Hemorrhage Many blood vessels must be cut in order to divide the stomach and to move the bowel. Any of these may later begin bleeding, either into the abdomen (intra-abdominal hemorrhage) or into the bowel itself (gastrointestinal hemorrhage). Transfusions may be needed, and re-operation is sometimes necessary. The use of blood thinners to prevent venous thromboembolic disease may actually increase the risk of hemorrhage slightly. Hernia A hernia is an abnormal opening, either within the abdomen or through the abdominal wall muscles. An internal hernia may result from surgery and re-arrangement of the bowel and is a cause of bowel obstruction. Antecolic antegastric Roux-en-Y gastric bypass surgery has been estimated to result in internal hernia in 0.2% of cases, mainly through Petersen's defect. An incisional hernia occurs when a surgical incision does not heal well; the muscles of the abdomen separate and allow protrusion of a sac-like membrane, which may contain bowel or other abdominal contents,