A new study from the American Cancer Society shows a sharp rise in colorectal cancer rates among younger Americans, and experts say there are a number of possible reasons behind the increase. Brook Silva-Braga reports.Subscribe to the "CBSN" Channel HERE: http://bit.ly/1Re2MgSWatch "CBSN" live HERE: http://cbsn.ws/1PlLpZ7Follow "CBSN" on Instagram HERE: http://bit.ly/1PO0dkxLike "CBSN" on Facebook HERE: http://on.fb.me/1o3Deb4Follow "CBSN" on Twitter HERE: http://bit.ly/1V4qhIuGet the latest news and best in original reporting from CBS News delivered to your inbox. Subscribe to newsletters HERE: http://cbsn.ws/1RqHw7TGet your news on the go! Download CBS News mobile apps HERE: http://cbsn.ws/1Xb1WC8Get new episodes of shows you love across devices the next day, stream local news live, and watch full seasons of CBS fan favorites anytime, anywhere with CBS All Access. Try it free! http://bit.ly/1OQA29B---CBSN is the first digital streaming news network that will allow Internet-connected consumers to watch live, anchored news coverage on their connected TV and other devices. At launch, the network is available 24/7 and makes all of the resources of CBS News available directly on digital platforms with live, anchored coverage 15 hours each weekday. CBSN. Always On.