Quebec healthcare institutions are facing an increase in patients’ request and asked to do more with less, impacting the healthcare staff by working harder and longer shifts. Despite efforts, waiting lists keep growing in number resulting in patients waiting long periods of time for a specific treatment. Lean methodologies, originally developed in the manufacturing industry, offer an alternative to do more with less. Lean focuses efforts on eliminating activities that do not add value from the patient perspective and builds more efficient processes to perform an activity.  This thesis proposes the use of Lean methodologies to improve the patient flow throughout the colorectal department at the Montreal General Hospital located in Montreal Quebec. A detail examination of the current processes of the department is analyzed and a proposed system is discussed with the use of value stream mapping and Lean principles. After rigorous data collection and analysis, initial improvements in the capacity of the department will increase in the common flow and colonoscopy loop by 20 patients per week and 60 patients per week respectively. In addition, Lead time will significantly decrease; up to 25% in short procedures, 20% in colonoscopies and 10% in surgeries.