The most common reason for pain during colonoscopy is the scope shaft looping back on itself stretching the walls of the colon.
Researchers at Tufts University's School of Engineering led by Associate Professor of Mechanical Engineering Caroline G.L. Cao, PhD, have developed a device that could potentially reduce that. As an endoscopist navigates the scope through the bends and turns in the colon, its tip can impinge against the colon wall. When this happens, the tip becomes stationary and is unable to move forward. As the physician applies more pressure, a loop can form in the length of scope behind the tip. Because the traditional endoscope provides only a frontal view during the procedure, the doctor cannot see the loop, much less easily maneuver the scope to remove it.
By outfitting an endoscope with fiber optic bend sensors and digital electronics that display its position and shape on a video monitor, the Tufts engineers have built a system that could serve as a visual navigation tool. If the scope begins to loop, they will see it instantaneously and then be able to make adjustments to straighten it out.
For further information:
http://www.endonurse.com/news/2011/04/researchers-try-to-make-colonoscopies-less-painful.aspx