Cardiopulmonary Exercise Testing and Preoperative Risk Stratification

The investigators would like to evaluate the use of cardiopulmonary exercise tests (CPX) in guiding the care pathway of patients undergoing colorectal operations. In the intervention group care will be guided by CPX results and in the control group care will be guided by the doctors assessment. The investigators would like to assess the impact of this on patient outcome, patient satisfaction and resource usage.