Pamela,
It sounds like this may be your husband's first colonoscopy? I don't know how familiar you are with the procedure, but the doctor will speak with you because your husband will be given drugs that will affect his memory. You're the only one that will remember everything that the doctor says; even if he tells your husband, he might not remember everything.
Both of my parents had colon cancer and I've been through many colonoscopies with them. Given that there are several possible causes for the bleeding, the doctor may or may not be able to give you a definite answer following the procedure. If the doctor does find something like a polyp, it can be removed during the procedure, but as with any other type of suspicious tissue, only a biopsy can determine whether or not the tissue is cancerous.
To answer your question regarding what to ask the doctor, it of course depends upon what is found during the procedure. Usually, doctors schedule several of these endoscopic procedures in series, so they don't spend too much time discussing what they've found. In both my parent's cases, the doctor didn't need to see the biopsy to know that they had colon cancer.
The worst part of a colonoscopy is the preparation. He's just about finished with the preparation step, so let's hope that whatever is found can be either corrected during the procedure or is something other than cancer.
We'll be thinking about you folks tomorrow, so please let us know how he's doing whenever it's convenient!
Ed K.