It sounds like you’re a good part of the way there - I’m glad you have a hematologist. Two other things: First, a stool occult blood test is quite trivial, at least at the yes/no level. It should cost about $1.49, but who knows what they’ll charge. Second, my only negative experience during my upper GI endoscopy was that the anesthesia relaxed my anal sphincter, which I hadn’t expected, and there were no prep instructions, so it was a bit messy - I might eat lightly/liquids and/or do a tap water enema beforehand if I have another one.