What Causes Blood In Stool While Having Colon Cancer?

obviously colon cancer spreads, when not caught early, to the liver, then further on north through the lymph system. But are there any cancers that typically spread TO the colon? My daughter is 19 and has had blood in her stool for the last 2 months I was horrified to learn today. My Dad died of colon cancer, and I have a female cousin on each side that has died of colon cancer. I am a man 50 years old. My cousins at diagnosis were 38 and 54 respectively with the standard 2 year fight prior to passing. Her sysmptoms are only blood but a LOT of it. Her symptoms do not seem to match Chrons, colitis, divirticulitis, or IBS. Hence my question of inbound cancer to the colon...