For patients undergoing colorectal surgery, post-operative pulmonary complications (PPCs) are common. PPCs are associated with increased morbidity and mortality, as well as prolonged hospital stays and healthcare costs. Pulmonary exercise in the pre-operative setting is thought to improve pulmonary fitness and decrease incidence of PPCs. Use of an oscillating positive expiratory pressure (OPEP) device sees patients improve their respiratory fitness through prescribed usage of a handheld instrument that exercises pulmonary muscles while breathing. Here, the investigators propose a pilot randomized-controlled trial (RCT) to evaluate the feasibility of a large scale study that would examine the effect of preoperative OPEP device exercises in preventing PPCs for patients undergoing elective colorectal surgery.

Inclusion Criteria:

• Patients must be 18 years of age or older, and scheduled for an elective colorectal procedure at London Health Science Center (LHSC). Informed consent must be obtained.

Exclusion Criteria:

• Patients unable to perform written consent will be excluded. The investigators will not include colorectal procedures performed for urgent or emergent indications. Patients with advanced pulmonary disease necessitating home oxygen pre-operatively will be excluded. Patients that are pregnant will be excluded.