The actual study's purpose is to find out if rectal cancer surgery can be performed without traditionally bowel preparation. Nutritional drinks are to be used instead of traditional bowel preparation. Patients are randomized into two groups, stratification for stricture, malnutrition and laparoscopic surgery and each group should either bee treated with traditional bowel preparation, Laxabon® (A) or nutritional drinks, Fresubin Energy drink (B) before surgery. Patients in subgroup B take nutritional drinks seven days before surgery instead of ordinary food. Bowel purity degree is measured peroperatively.