James Van Der Beek has been diagnosed with colorectal cancer. The ‘Dawson’s Creek’ star, 47, has been “privately dealing with the diagnosis” and has reassured fans he is making the necessary “steps to resolve it” and is feeling optimistic. He told PEOPLE: “I have colorectal cancer. I’ve been privately dealing with this diagnosis and have been taking steps to resolve it, with the support of my incredible family. “There’s reason for optimism, and I’m feeling good.” Colorectal cancer develops in either the rectum or the colon. James didn’t disclose what stage his cancer is or his course of treatm…