Rationale: Colorectal cancer is the fourth most common cause of cancer death worldwide, estimated to be responsible for almost 610,000 deaths in 2008. Surgery remains the predominant curative treatment type for colorectal cancer, but has a major impact on the patient's wellbeing by demanding large amounts of metabolic reserves. This can lead to the development of frequently observed and severe postoperative complications. The most important complication after colorectal surgery is anastomotic leakage (AL), which has an incidence of 8-15% in the Netherlands. AL is associated with high short-term mortality rates of up to 40%. Even though many attempts have been made to reduce the incidence of this dreaded complication, none of these interventions have been successful so far. Despite proper patient selection and improvement in surgical techniques, the percentage of AL has been stable for years.