In our institution, patients undergoing surgery for cancer in the rectum are often prepared with energy drinks in order to receive a higher energy level before the operation. As a result of this the patients often avoid nausea and have a better intestinal function after surgery and less complications. We think that this treatment has worked well on the patients but no scientific studies have been done on these patients. As a complementary result of the treatment with nutritional drinks we have found that the colon is empty already after a short time of treatment.