Bowel preparation was not routinely used in open surgery, whereas in patients undergoing laparoscopic resection two litres of sodium-sulfate / macrogol solution (Cololyt®, Spirig Pharma AG, Switzerland) was administered. Standard colorectal surgery was performed in all patients. In open surgery a midline incision was used for laparotomy. In laparoscopic resections a four-port technique with removal of the specimen through a small transverse incision in the lower abdomen was used. All patients received perioperative single shot antibiotics, cefuroxime 1.5 g and metronidazole 1g. Nasogastric tube (NGT) was scheduled to be removed at the end of surgery. Postoperative treatment was not changed during the study. All patients received postoperatively a basic analgesia of 500 to 1000 mg oral paracetamol every 6 h; additionally, metamizol was administrated intravenously or orally as needed.