Colorectal Cancer Community

My fiance is going in for a colonoscopy later this week, and until then her doctors said there's "no use in speculating" what's wrong with her. In the meantime I am pretty frightened, though I don't want to tell her that. So I have come to this message board to vent and hopefully for some solace or guidance.
She has had what she thought were IBS symptoms for about a year now. Constpation, trapped gas, abdominal discomfort, occasional nauseea. Her doc did a few tests and said there was nothing physically wrong and treated it as IBS. Certain dietary changes have alleviated the symptoms somewhat but the laxatives were not particularly helpful.
Recently she found blood in her stool for the first time. She went back to the doctor, who ran a blood test. She had a slightly high "sed. rate" which I read indicates inflammation. The doctor said she was concerned and ordered a colonoscopy.
My fiance is only 25 years old. Her mother died in her 40s of cancer. Her mother's cancer was so advanced at the time of its discovery that they don't know where it originated.
Although crohn's is what the doctor said she is primarily concerned about, it seems like her symptoms are pretty consistent with colon cancer. With her family history I am particuarly worried.
I don't know how I'll make it through the next few days anticipating the procedure. I don't want to let her know how concerned I am that it is cancer because I want to help her, not add to her anxiety. It is tough for me not having my best friend to talk to about this. Any thoughts would be appreciated. Thank you.