Colon and rectal cancers are increasing among younger adults, according to new research. At the same time, incidents of colon and rectal cancers in those over 50 years of age have been decreasing slightly. Researchers aren’t sure why rates are increasing among young adults, but attribute the decrease in those older adults to the increase in screening and removal of suspicious growths before they’re able to turn malignant. Should things continue on their current path, researchers believe colon and rectal cancer cases in those aged 20 to 34 years could come close to doubling in the next 15 years. For 35 to 49 year olds, those rates could increase by 28 to 46 percent.