Yesterday, NBCWashington.com got exclusive access into the operating room during Butterstick’s colonoscopy — and there’s good news: the big guy’s got a completely clean bill of health. View more news videos at: http://www.nbcwashington.com/video. The procedure will also help vets understand further how the panda bear’s bamboo diet affects their digestive system. While it’s not the most glamorous thing in the world, ‘Stick’s big fluffy black ear blocking the scope monitor while his big tongue hangs…