Gastric Bypass is a combined operation in which a 1ounce pouch is made and the remaining stomach and portion of the small bowel are bypassed. The patient is then restricted and eats smaller portions, increasing satiety and reducing absorption. Patients can expect to reduce their excess body weight by 80-85% over 18 months. Medical conditions are dramatically improved, such as diabetes, hypertension, hyperlipidemia, and seep apnea. This procedure provides negative feedback for most patients who ingest too many simple sugars, fats or overly processed foods. The contour of the body may change and patients may choose to have plastic surgery. Hair loss may occur during the first 3-6 months, however this usually resolves by 1 year. There is a 1% risk of ulcer formation in the pouch, especially if the patient takes NSAIDs or smokes. The risk of iron deficiency in menstruating women is possible.