I'm sorry to hear that you're having so much pain.
I'm not sure why it would take so long to get results of a colonoscopy, I'm guessing biopsies, since the physician can give immediate results to the colonoscopy.
I didn't have problems with bleeding, but was treated for anemia for several years with testing done on just about everything trying to find the source of my loss of hemoglobin.
You could try a gluten-free diet, but I would caution you to maybe wait until you speak to your doctor. If they decide to test you specifically for celiac disease, as was stated that's not seen on colonoscopy, you'd have to have an endoscopy. Either way, you have to be consuming gluten when you're tested.
Sending you healing thoughts that your pain lessens and you are able to get some answers.