A surgical method of treating a patient is disclosed. The method comprises the steps of: cutting the patient's skin and abdominal wall; dissecting an area of the patient's intestine; and dissecting a portion of the dissected intestinal area such that intestinal mesentery connected thereto is opened in such a way that supply of blood through the mesentery to the dissected intestinal area is maintained as much as possible on both sides of the dissected portion. The method further comprises the steps of dividing the patient's intestine in the dissected portion so as to create an upstream part of the intestine with a first intestinal opening and a downstream part of the intestine with a second intestinal opening with the mesentery still maintaining a tissue connection between the upstream and downstream intestine parts.