Endoscopy is a minimally invasive procedure using instruments that pass through the body for diagnostic purposes and minimizes the risks associated with open surgery. Colonoscopy can viewed as an endoscopic procedure of the colon. Colonoscopy may cause extreme discomfort to the patient and also carries the risks of perforating the lining of the colon, splenic ruptures, or bleeding. The technology is an endoscope that has an exoskeleton structure of controllable stiffness and a highly flexible stem. The device saves the patient from the pain caused by the shaft of a colonoscope when it is guided from the anus to the end of the sigmoid colon. The stiffenable sheath guides the shaft of the colonoscope up to the end of the sigmoid colon to avoid looping the shaft of the colonoscope. A prototype of the device was built and tested to validate its effectiveness. In order to further improve the performance of the device, skilled endoscopists tested and validated the device using a colonoscopy training model. The colonoscopy training model is comprised of a configurable rubber colon, a human torso, a display, and sensing part. It measures the forces caused by the distal tip and the shaft of the colonoscope and the pressure to open up the lumen. The force sensors at the rubber colon constraints measure the forces, and the real-time display panel will show the results to the colonoscopist and record the data for analysis. The endoscopy sheath device improves the process of endoscopy by reducing the mechanical trauma and loops caused by the shaft of the endoscope. With the guide provided by the colonoscope sheath, the forces to the constraints of a colon are significantly decreased in the sigmoid colon. The colonoscope sheath helps to reduce the force to constraints of the colon and isolates the direct contact between the shaft of a colonoscope and a colon wall up to the end of the sigmoid colon. For the complicated shape of the colon, the endoscopy sheath also solved possible looping problems. The colonoscope training model effectively measures the forces and makes it possible to validate the effectiveness of the endoscopy sheath.