James Van Der Beek Battling Colorectal Cancer

James Van Der Beek is batting colorectal cancer ... TMZ has confirmed. The 47-year-old actor, best known for "Dawson's Creek," was recently diagnosed with the disease -- telling People he's receiving treatment to resolve it. Van Der Beek says -- despite the scary diagnosis -- there's reason to be optimistic. He doesn't clarify exactly what he means here, but he adds he's feeling good. According to the American…