A natural or artificial connection, usually by surgery, of two tubular channels that may or may not normally be joined. An anastomosis can involve the intestines, arteries, or veins. Most commonly, a natural anastomosis takes the form of two blood vessels converging. Surgical anastomosis is performed to treat various disorders. For example, it is often used to treat intestinal obstruction. In this procedure, the diseased part of the intestine is removed and the remaining healthy sections are joined together.