You are correct, my doctors called the sigmoidoscopy a "short scope". I didn't get a blood test however, I did not know that was typically included.
Do you have any insight on the differences in the bleeding? Mine was a few red streaks mixed in the stool and no drops in the water, with some blood on the toliet paper. It did not happen every movenent during "outbreaks".
A sigmoidoscopy is a fairly good test (more than I had for my original hemorrhoids), so you're already waaaay ahead of where I was.
For me the hemorrhoid blood was very bright red--like if I had a bad paper cut or cut myself shaving my legs (for guys I suppose it'd be like shaving whiskers). It was essentially liquid, almost like red food dye. When it was in the bowl it colored the water, rather than the stool, and looked like watercolor paint on the toilet paper.
My more recent bleeding was thicker, more mucos-y and the color of sun dried tomatoes. It wasn't liquidy, so it colored the stool, not the water (the water remained clear and colorless). There was some on the toilet paper, but not much. Like I said, taking a picture really helped my GI, since everyone's perception of color is different. Now, my friend had almost exactly the same symptoms as I did--but she didn't have cancer, or even polyps, so don't freak out
Still, she needed a colonoscopy for a proper diagnosis & treatment.
Honestly, in your case I'd get another GI and press on about a full colonoscopy more for relief/diagnosis of your other symptoms, rather than out of fear of cancer. Digestive issues very much affect quality of life, and you should have a doctor who will work with you so you can get relief. That may mean diet changes, etc, but you're doing right getting checked out--the least you should have is a doctor who respects you enough to take you seriously.