Clinical Research Directory

Inclusion Criteria: * criteria for bariatric surgery published in 1991 for the National Institutes of Health of the USA. * Body mass index (BMI)\> 40 and \<55 kg/m2 * Obesity for more than 5 years of evolution * Fail in medical supervised weight loss program * patient knowing of the mechanism of weight loss after surgery and agreement to collaborate with medical recommendations, diet, medical treatment, as well as the visit established in the follow up program * patient accepting that surgery objective is not to achieve the ideal weight. * signed specific informed consent * women will agree in avoid gestation during one year after surgery Exclusion Criteria: * Patients unable to sign the informed consent form because of a mental disorder. * endocrine diseases causing obesity * unstable mental disorder, evaluated for a psychiatry MD. * high anesthetic risk making surgery too risky. * Malignant neoplasm * Inflammatory bowel disease * Severe liver disease * Digestive disease that makes unwise the bypass technique (mainly gastric illness that may required upper endoscopy for control) * abdominal wall hernias * Symptomatic biliary pathology that requires cholechistectomy at the same time of the bariatric surgery * any known pathology that requieres or recomend simultaneous surgery at the time of the bariatric surgery.